Deprecate cognitive_complexity lint

This also deprecates the `cyclomatic_complexity` lint which had been
renamed into `cognitive_complexity` back in 2019.

Author: samueltardieu

CHANGELOG.md

@@ -6520,7 +6520,6 @@ Released 2018-09-13
 [`check-incompatible-msrv-in-tests`]: https://doc.rust-lang.org/clippy/lint_configuration.html#check-incompatible-msrv-in-tests
 [`check-inconsistent-struct-field-initializers`]: https://doc.rust-lang.org/clippy/lint_configuration.html#check-inconsistent-struct-field-initializers
 [`check-private-items`]: https://doc.rust-lang.org/clippy/lint_configuration.html#check-private-items
-[`cognitive-complexity-threshold`]: https://doc.rust-lang.org/clippy/lint_configuration.html#cognitive-complexity-threshold
 [`disallowed-macros`]: https://doc.rust-lang.org/clippy/lint_configuration.html#disallowed-macros
 [`disallowed-methods`]: https://doc.rust-lang.org/clippy/lint_configuration.html#disallowed-methods
 [`disallowed-names`]: https://doc.rust-lang.org/clippy/lint_configuration.html#disallowed-names

book/src/lint_configuration.md

@@ -475,16 +475,6 @@ Whether to also run the listed lints on private items.
 * [`unnecessary_safety_doc`](https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_safety_doc)
 
 
-## `cognitive-complexity-threshold`
-The maximum cognitive complexity a function can have
-
-**Default Value:** `25`
-
----
-**Affected lints:**
-* [`cognitive_complexity`](https://rust-lang.github.io/rust-clippy/master/index.html#cognitive_complexity)
-
-
 ## `disallowed-macros`
 The list of disallowed macros, written as fully qualified paths.
 

clippy_config/src/conf.rs

@@ -566,14 +566,6 @@ define_Conf! {
     /// Whether to also run the listed lints on private items.
     #[lints(missing_errors_doc, missing_panics_doc, missing_safety_doc, unnecessary_safety_doc)]
     check_private_items: bool = false,
-    /// The maximum cognitive complexity a function can have
-    #[lints(cognitive_complexity)]
-    cognitive_complexity_threshold: u64 = 25,
-    /// DEPRECATED LINT: CYCLOMATIC_COMPLEXITY.
-    ///
-    /// Use the Cognitive Complexity lint instead.
-    #[conf_deprecated("Please use `cognitive-complexity-threshold` instead", cognitive_complexity_threshold)]
-    cyclomatic_complexity_threshold: u64 = 25,
     /// The list of disallowed macros, written as fully qualified paths.
     ///
     /// **Fields:**

clippy_lints/src/cognitive_complexity.rs

@@ -78,7 +78,6 @@ pub static LINTS: &[&::declare_clippy_lint::LintInfo] = &[
     crate::checked_conversions::CHECKED_CONVERSIONS_INFO,
     crate::cloned_ref_to_slice_refs::CLONED_REF_TO_SLICE_REFS_INFO,
     crate::coerce_container_to_any::COERCE_CONTAINER_TO_ANY_INFO,
-    crate::cognitive_complexity::COGNITIVE_COMPLEXITY_INFO,
     crate::collapsible_if::COLLAPSIBLE_ELSE_IF_INFO,
     crate::collapsible_if::COLLAPSIBLE_IF_INFO,
     crate::collection_is_never_read::COLLECTION_IS_NEVER_READ_INFO,

clippy_lints/src/declared_lints.rs

@@ -16,6 +16,10 @@ macro_rules! declare_with_version {
 declare_with_version! { DEPRECATED(DEPRECATED_VERSION) = [
     #[clippy::version = "1.30.0"]
     ("clippy::assign_ops", "compound operators are harmless and linting on them is not in scope for clippy"),
+    #[clippy::version = "1.90.0"]
+    ("clippy::cognitive_complexity", "`excessive_nesting` and `too_many_lines` lints allow for finer-grain controls"),
+    #[clippy::version = "1.35.0"]
+    ("clippy::cyclomatic_complexity", "`excessive_nesting` and `too_many_lines` lints allow for finer-grain controls"),
     #[clippy::version = "pre 1.29.0"]
     ("clippy::extend_from_slice", "`Vec::extend_from_slice` is no longer faster than `Vec::extend` due to specialization"),
     #[clippy::version = "1.86.0"]
@@ -69,8 +73,6 @@ declare_with_version! { RENAMED(RENAMED_VERSION) = [
     #[clippy::version = ""]
     ("clippy::const_static_lifetime", "clippy::redundant_static_lifetimes"),
     #[clippy::version = ""]
-    ("clippy::cyclomatic_complexity", "clippy::cognitive_complexity"),
-    #[clippy::version = ""]
     ("clippy::derive_hash_xor_eq", "clippy::derived_hash_with_manual_eq"),
     #[clippy::version = ""]
     ("clippy::disallowed_method", "clippy::disallowed_methods"),

clippy_lints/src/deprecated_lints.rs

@@ -96,7 +96,6 @@ mod cfg_not_test;
 mod checked_conversions;
 mod cloned_ref_to_slice_refs;
 mod coerce_container_to_any;
-mod cognitive_complexity;
 mod collapsible_if;
 mod collection_is_never_read;
 mod comparison_chain;
@@ -537,7 +536,6 @@ pub fn register_lint_passes(store: &mut rustc_lint::LintStore, conf: &'static Co
     store.register_late_pass(|_| Box::<no_effect::NoEffect>::default());
     store.register_late_pass(|_| Box::new(temporary_assignment::TemporaryAssignment));
     store.register_late_pass(move |_| Box::new(transmute::Transmute::new(conf)));
-    store.register_late_pass(move |_| Box::new(cognitive_complexity::CognitiveComplexity::new(conf)));
     store.register_late_pass(move |_| Box::new(escape::BoxedLocal::new(conf)));
     store.register_late_pass(move |_| Box::new(vec::UselessVec::new(conf)));
     store.register_late_pass(move |_| Box::new(panic_unimplemented::PanicUnimplemented::new(conf)));

clippy_lints/src/lib.rs

@@ -1,6 +1,6 @@
 # Expect errors from these deprecated configs
-cyclomatic-complexity-threshold = 2
 blacklisted-names = [ "..", "wibble" ]
+lint-inconsistent-struct-field-initializers = true
 
 # that one is white-listed
 [third-party]

tests/ui-toml/conf_deprecated_key/clippy.toml

@@ -1,14 +1,3 @@
-#![allow(clippy::uninlined_format_args)]
+//@error-in-other-file:
 
 fn main() {}
-
-#[warn(clippy::cognitive_complexity)]
-fn cognitive_complexity() {
-    //~^ cognitive_complexity
-    let x = vec![1, 2, 3];
-    for i in x {
-        if i == 1 {
-            println!("{}", i);
-        }
-    }
-}

tests/ui-toml/conf_deprecated_key/conf_deprecated_key.rs

@@ -1,24 +1,14 @@
-warning: error reading Clippy's configuration file: deprecated field `cyclomatic-complexity-threshold`. Please use `cognitive-complexity-threshold` instead
-  --> $DIR/tests/ui-toml/conf_deprecated_key/clippy.toml:2:1
-   |
-LL | cyclomatic-complexity-threshold = 2
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-
 warning: error reading Clippy's configuration file: deprecated field `blacklisted-names`. Please use `disallowed-names` instead
-  --> $DIR/tests/ui-toml/conf_deprecated_key/clippy.toml:3:1
+  --> $DIR/tests/ui-toml/conf_deprecated_key/clippy.toml:2:1
    |
 LL | blacklisted-names = [ "..", "wibble" ]
    | ^^^^^^^^^^^^^^^^^
 
-error: the function has a cognitive complexity of (3/2)
-  --> tests/ui-toml/conf_deprecated_key/conf_deprecated_key.rs:6:4
-   |
-LL | fn cognitive_complexity() {
-   |    ^^^^^^^^^^^^^^^^^^^^
+warning: error reading Clippy's configuration file: deprecated field `lint-inconsistent-struct-field-initializers`. Please use `check-inconsistent-struct-field-initializers` instead
+  --> $DIR/tests/ui-toml/conf_deprecated_key/clippy.toml:3:1
    |
-   = help: you could split it up into multiple smaller functions
-   = note: `-D clippy::cognitive-complexity` implied by `-D warnings`
-   = help: to override `-D warnings` add `#[allow(clippy::cognitive_complexity)]`
+LL | lint-inconsistent-struct-field-initializers = true
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-error: aborting due to 1 previous error; 2 warnings emitted
+warning: 2 warnings emitted