Build lint lists once and the reuse them to update files

2 files changed, 43 insertions, 40 deletions

diff --git a/clippy_dev/src/lib.rs b/clippy_dev/src/lib.rs
index 4531d9b39c0..bec415aae94 100644
--- a/clippy_dev/src/lib.rs
+++ b/clippy_dev/src/lib.rs
@@ -62,13 +62,25 @@ impl Lint {
     }
 
     /// Returns all non-deprecated lints and non-internal lints
-    pub fn usable_lints(lints: impl Iterator<Item = Self>) -> impl Iterator<Item = Self> {
-        lints.filter(|l| l.deprecation.is_none() && !l.group.starts_with("internal"))
+    #[must_use]
+    pub fn usable_lints(lints: &[Self]) -> Vec<Self> {
+        lints
+            .iter()
+            .filter(|l| l.deprecation.is_none() && !l.group.starts_with("internal"))
+            .cloned()
+            .collect()
     }
 
     /// Returns all internal lints (not `internal_warn` lints)
-    pub fn internal_lints(lints: impl Iterator<Item = Self>) -> impl Iterator<Item = Self> {
-        lints.filter(|l| l.group == "internal")
+    #[must_use]
+    pub fn internal_lints(lints: &[Self]) -> Vec<Self> {
+        lints.iter().filter(|l| l.group == "internal").cloned().collect()
+    }
+
+    /// Returns all deprecated lints
+    #[must_use]
+    pub fn deprecated_lints(lints: &[Self]) -> Vec<Self> {
+        lints.iter().filter(|l| l.deprecation.is_some()).cloned().collect()
     }
 
     /// Returns the lints in a `HashMap`, grouped by the different lint groups
@@ -80,9 +92,8 @@ impl Lint {
 
 /// Generates the Vec items for `register_lint_group` calls in `clippy_lints/src/lib.rs`.
 #[must_use]
-pub fn gen_lint_group_list(lints: &[Lint]) -> Vec<String> {
+pub fn gen_lint_group_list<'a>(lints: impl Iterator<Item = &'a Lint>) -> Vec<String> {
     lints
-        .into_iter()
         .filter_map(|l| {
             if l.deprecation.is_some() {
                 None
@@ -96,9 +107,8 @@ pub fn gen_lint_group_list(lints: &[Lint]) -> Vec<String> {
 
 /// Generates the `pub mod module_name` list in `clippy_lints/src/lib.rs`.
 #[must_use]
-pub fn gen_modules_list(lints: &[Lint]) -> Vec<String> {
+pub fn gen_modules_list<'a>(lints: impl Iterator<Item = &'a Lint>) -> Vec<String> {
     lints
-        .iter()
         .map(|l| &l.module)
         .unique()
         .map(|module| format!("pub mod {};", module))
@@ -108,9 +118,8 @@ pub fn gen_modules_list(lints: &[Lint]) -> Vec<String> {
 
 /// Generates the list of lint links at the bottom of the README
 #[must_use]
-pub fn gen_changelog_lint_list(lints: &[Lint]) -> Vec<String> {
+pub fn gen_changelog_lint_list<'a>(lints: impl Iterator<Item = &'a Lint>) -> Vec<String> {
     lints
-        .iter()
         .sorted_by_key(|l| l.name.clone())
         .filter_map(|l| {
             if l.group.starts_with("internal") {
@@ -124,9 +133,8 @@ pub fn gen_changelog_lint_list(lints: &[Lint]) -> Vec<String> {
 
 /// Generates the `register_removed` code in `./clippy_lints/src/lib.rs`.
 #[must_use]
-pub fn gen_deprecated(lints: &[Lint]) -> Vec<String> {
+pub fn gen_deprecated<'a>(lints: impl Iterator<Item = &'a Lint>) -> Vec<String> {
     lints
-        .iter()
         .filter_map(|l| {
             l.clone().deprecation.map(|depr_text| {
                 vec![
@@ -142,11 +150,10 @@ pub fn gen_deprecated(lints: &[Lint]) -> Vec<String> {
 }
 
 #[must_use]
-pub fn gen_register_lint_list(lints: &[Lint]) -> Vec<String> {
+pub fn gen_register_lint_list<'a>(lints: impl Iterator<Item = &'a Lint>) -> Vec<String> {
     let pre = "    store.register_lints(&[".to_string();
     let post = "    ]);".to_string();
     let mut inner = lints
-        .iter()
         .map(|l| format!("        &{}::{},", l.module, l.name.to_uppercase()))
         .sorted()
         .collect::<Vec<String>>();
@@ -421,7 +428,7 @@ fn test_usable_lints() {
         None,
         "module_name",
     )];
-    assert_eq!(expected, Lint::usable_lints(lints.into_iter()).collect::<Vec<Lint>>());
+    assert_eq!(expected, Lint::usable_lints(&lints));
 }
 
 #[test]
@@ -457,7 +464,7 @@ fn test_gen_changelog_lint_list() {
         format!("[`should_assert_eq`]: {}#should_assert_eq", DOCS_LINK.to_string()),
         format!("[`should_assert_eq2`]: {}#should_assert_eq2", DOCS_LINK.to_string()),
     ];
-    assert_eq!(expected, gen_changelog_lint_list(&lints));
+    assert_eq!(expected, gen_changelog_lint_list(lints.iter()));
 }
 
 #[test]
@@ -492,7 +499,7 @@ fn test_gen_deprecated() {
     .into_iter()
     .map(String::from)
     .collect();
-    assert_eq!(expected, gen_deprecated(&lints));
+    assert_eq!(expected, gen_deprecated(lints.iter()));
 }
 
 #[test]
@@ -507,7 +514,7 @@ fn test_gen_modules_list() {
         "pub mod another_module;".to_string(),
         "pub mod module_name;".to_string(),
     ];
-    assert_eq!(expected, gen_modules_list(&lints));
+    assert_eq!(expected, gen_modules_list(lints.iter()));
 }
 
 #[test]
@@ -523,5 +530,5 @@ fn test_gen_lint_group_list() {
         "        LintId::of(&module_name::INTERNAL),".to_string(),
         "        LintId::of(&module_name::SHOULD_ASSERT_EQ),".to_string(),
     ];
-    assert_eq!(expected, gen_lint_group_list(&lints));
+    assert_eq!(expected, gen_lint_group_list(lints.iter()));
 }
diff --git a/clippy_dev/src/update_lints.rs b/clippy_dev/src/update_lints.rs
index be565700b01..a9a70929942 100644
--- a/clippy_dev/src/update_lints.rs
+++ b/clippy_dev/src/update_lints.rs
@@ -14,14 +14,14 @@ pub enum UpdateMode {
 pub fn run(update_mode: UpdateMode) {
     let lint_list: Vec<Lint> = gather_all().collect();
 
-    let internal_lints = Lint::internal_lints(lint_list.clone().into_iter());
-
-    let usable_lints: Vec<Lint> = Lint::usable_lints(lint_list.clone().into_iter()).collect();
-    let usable_lint_count = round_to_fifty(usable_lints.len());
-
+    let internal_lints = Lint::internal_lints(&lint_list);
+    let deprecated_lints = Lint::deprecated_lints(&lint_list);
+    let usable_lints = Lint::usable_lints(&lint_list);
     let mut sorted_usable_lints = usable_lints.clone();
     sorted_usable_lints.sort_by_key(|lint| lint.name.clone());
 
+    let usable_lint_count = round_to_fifty(usable_lints.len());
+
     let mut file_change = replace_region_in_file(
         Path::new("src/lintlist/mod.rs"),
         "begin lint list",
@@ -61,7 +61,7 @@ pub fn run(update_mode: UpdateMode) {
         "<!-- end autogenerated links to lint list -->",
         false,
         update_mode == UpdateMode::Change,
-        || gen_changelog_lint_list(&lint_list),
+        || gen_changelog_lint_list(usable_lints.iter().chain(deprecated_lints.iter())),
     )
     .changed;
 
@@ -71,7 +71,7 @@ pub fn run(update_mode: UpdateMode) {
         "end deprecated lints",
         false,
         update_mode == UpdateMode::Change,
-        || gen_deprecated(&lint_list),
+        || gen_deprecated(deprecated_lints.iter()),
     )
     .changed;
 
@@ -81,7 +81,7 @@ pub fn run(update_mode: UpdateMode) {
         "end register lints",
         false,
         update_mode == UpdateMode::Change,
-        || gen_register_lint_list(&usable_lints),
+        || gen_register_lint_list(usable_lints.iter().chain(internal_lints.iter())),
     )
     .changed;
 
@@ -91,7 +91,7 @@ pub fn run(update_mode: UpdateMode) {
         "end lints modules",
         false,
         update_mode == UpdateMode::Change,
-        || gen_modules_list(&usable_lints),
+        || gen_modules_list(usable_lints.iter()),
     )
     .changed;
 
@@ -104,15 +104,11 @@ pub fn run(update_mode: UpdateMode) {
         update_mode == UpdateMode::Change,
         || {
             // clippy::all should only include the following lint groups:
-            let all_group_lints = usable_lints
-                .clone()
-                .into_iter()
-                .filter(|l| {
-                    l.group == "correctness" || l.group == "style" || l.group == "complexity" || l.group == "perf"
-                })
-                .collect::<Vec<_>>();
-
-            gen_lint_group_list(&all_group_lints)
+            let all_group_lints = usable_lints.iter().filter(|l| {
+                l.group == "correctness" || l.group == "style" || l.group == "complexity" || l.group == "perf"
+            });
+
+            gen_lint_group_list(all_group_lints)
         },
     )
     .changed;
@@ -125,7 +121,7 @@ pub fn run(update_mode: UpdateMode) {
             r#"\]\);"#,
             false,
             update_mode == UpdateMode::Change,
-            || gen_lint_group_list(&lints),
+            || gen_lint_group_list(lints.iter()),
         )
         .changed;
     }
@@ -140,8 +136,8 @@ pub fn run(update_mode: UpdateMode) {
 }
 
 pub fn print_lints() {
-    let lint_list = gather_all();
-    let usable_lints: Vec<Lint> = Lint::usable_lints(lint_list).collect();
+    let lint_list: Vec<Lint> = gather_all().collect();
+    let usable_lints = Lint::usable_lints(&lint_list);
     let usable_lint_count = usable_lints.len();
     let grouped_by_lint_group = Lint::by_lint_group(usable_lints.into_iter());