Add unstable cargo lint tables and make use of clippy

Cargo.toml

@@ -92,3 +92,48 @@ serde_json = "1.0.94"
 triomphe = { version = "0.1.8", default-features = false, features = ["std"] }
 
 rustc_lexer = { version = "0.1.0", package = "ra-ap-rustc_lexer" }
+
+[workspace.lints.rust]
+rust_2018_idioms = "warn"
+unused_lifetimes = "warn"
+semicolon_in_expressions_from_macros = "warn"
+
+[workspace.lints.clippy]
+# complexity lints
+complexity = { level = "warn", priority = -1 }
+# Should be tackled at some point where relevant
+too_many_arguments = "allow"
+# Should be tackled at some point
+type_complexity = "allow"
+
+# correctness lints
+correctness = { level = "deny", priority = -1 }
+
+# perf lints
+perf = { level = "deny", priority = -1 }
+
+# style lints
+style = { level = "warn", priority = -1 }
+# () makes a fine error in most cases
+result_unit_err = "allow"
+# We don't expose public APIs that matter like this
+len_without_is_empty = "allow"
+# we currently prefer explicit control flow return over `...?;` statements whose result is unused
+question_mark = "allow"
+# We have macros that rely on this currently
+enum_variant_names = "allow"
+# Builder pattern disagrees
+new_ret_no_self = "allow"
+
+# suspicious lints
+suspicious = { level = "warn", priority = -1 }
+
+# suspicious lints
+restriction = { level = "allow", priority = -1 }
+# Remove the tidy test once the lint table is stable
+dbg_macro = "warn"
+todo = "warn"
+unimplemented = "warn"
+rc_buffer = "warn"
+# FIXME enable this, we use this pattern a lot so its annoying work ...
+# str_to_string = "warn"

crates/base-db/Cargo.toml

@@ -27,3 +27,6 @@ syntax.workspace = true
 test-utils.workspace = true
 tt.workspace = true
 vfs.workspace = true
+
+[lints]
+workspace = true

crates/base-db/src/fixture.rs

@@ -116,7 +116,7 @@ impl ChangeFixture {
         let toolchain = toolchain
             .map(|it| {
                 ReleaseChannel::from_str(&it)
-                    .unwrap_or_else(|| panic!("unknown release channel found: {it}"))
+                    .unwrap_or_else(|()| panic!("unknown release channel found: {it}"))
             })
             .unwrap_or(ReleaseChannel::Stable);
         let mut change = Change::new();
@@ -131,7 +131,7 @@ impl ChangeFixture {
 
         let mut file_set = FileSet::default();
         let mut current_source_root_kind = SourceRootKind::Local;
-        let source_root_prefix = "/".to_string();
+        let source_root_prefix = "/".to_owned();
         let mut file_id = FileId(0);
         let mut roots = Vec::new();
 
@@ -245,7 +245,7 @@ impl ChangeFixture {
             file_id.0 += 1;
 
             let mut fs = FileSet::default();
-            fs.insert(core_file, VfsPath::new_virtual_path("/sysroot/core/lib.rs".to_string()));
+            fs.insert(core_file, VfsPath::new_virtual_path("/sysroot/core/lib.rs".to_owned()));
             roots.push(SourceRoot::new_library(fs));
 
             change.change_file(core_file, Some(Arc::from(mini_core.source_code())));
@@ -255,7 +255,7 @@ impl ChangeFixture {
             let core_crate = crate_graph.add_crate_root(
                 core_file,
                 Edition::Edition2021,
-                Some(CrateDisplayName::from_canonical_name("core".to_string())),
+                Some(CrateDisplayName::from_canonical_name("core".to_owned())),
                 None,
                 Default::default(),
                 Default::default(),
@@ -283,7 +283,7 @@ impl ChangeFixture {
             let mut fs = FileSet::default();
             fs.insert(
                 proc_lib_file,
-                VfsPath::new_virtual_path("/sysroot/proc_macros/lib.rs".to_string()),
+                VfsPath::new_virtual_path("/sysroot/proc_macros/lib.rs".to_owned()),
             );
             roots.push(SourceRoot::new_library(fs));
 
@@ -294,7 +294,7 @@ impl ChangeFixture {
             let proc_macros_crate = crate_graph.add_crate_root(
                 proc_lib_file,
                 Edition::Edition2021,
-                Some(CrateDisplayName::from_canonical_name("proc_macros".to_string())),
+                Some(CrateDisplayName::from_canonical_name("proc_macros".to_owned())),
                 None,
                 Default::default(),
                 Default::default(),
@@ -453,7 +453,7 @@ fn parse_crate(crate_str: String) -> (String, CrateOrigin, Option<String>) {
             },
             _ => panic!("Bad string for crate origin: {b}"),
         };
-        (a.to_owned(), origin, Some(version.to_string()))
+        (a.to_owned(), origin, Some(version.to_owned()))
     } else {
         let crate_origin = match LangCrateOrigin::from(&*crate_str) {
             LangCrateOrigin::Other => CrateOrigin::Local { repo: None, name: None },

crates/base-db/src/input.rs

@@ -282,13 +282,17 @@ impl ReleaseChannel {
             ReleaseChannel::Nightly => "nightly",
         }
     }
+}
+
+impl FromStr for ReleaseChannel {
+    type Err = ();
 
-    pub fn from_str(str: &str) -> Option<Self> {
-        Some(match str {
+    fn from_str(str: &str) -> Result<Self, Self::Err> {
+        Ok(match str {
             "" => ReleaseChannel::Stable,
             "nightly" => ReleaseChannel::Nightly,
             _ if str.starts_with("beta") => ReleaseChannel::Beta,
-            _ => return None,
+            _ => return Err(()),
         })
     }
 }

crates/cfg/Cargo.toml

@@ -29,3 +29,6 @@ derive_arbitrary = "1.2.2"
 # local deps
 mbe.workspace = true
 syntax.workspace = true
+
+[lints]
+workspace = true

crates/flycheck/Cargo.toml

@@ -24,3 +24,6 @@ command-group = "2.0.1"
 paths.workspace = true
 stdx.workspace = true
 toolchain.workspace = true
+
+[lints]
+workspace = true

crates/flycheck/src/lib.rs

@@ -513,6 +513,7 @@ impl CargoActor {
     }
 }
 
+#[allow(clippy::large_enum_variant)]
 enum CargoMessage {
     CompilerArtifact(cargo_metadata::Artifact),
     Diagnostic(Diagnostic),

crates/hir-def/Cargo.toml

@@ -51,3 +51,6 @@ expect-test = "1.4.0"
 
 # local deps
 test-utils.workspace = true
+
+[lints]
+workspace = true

crates/hir-def/src/attr.rs

@@ -379,7 +379,7 @@ fn parse_comma_sep<S>(subtree: &tt::Subtree<S>) -> Vec<SmolStr> {
 }
 
 impl AttrsWithOwner {
-    pub(crate) fn attrs_with_owner(db: &dyn DefDatabase, owner: AttrDefId) -> Self {
+    pub(crate) fn attrs_with_owner_query(db: &dyn DefDatabase, owner: AttrDefId) -> Self {
         Self { attrs: db.attrs(owner), owner }
     }
 

crates/hir-def/src/body.rs

@@ -242,12 +242,12 @@ impl Body {
                 }
             }
             Pat::Or(args) | Pat::Tuple { args, .. } | Pat::TupleStruct { args, .. } => {
-                args.iter().copied().for_each(|p| f(p));
+                args.iter().copied().for_each(&mut f);
             }
             Pat::Ref { pat, .. } => f(*pat),
             Pat::Slice { prefix, slice, suffix } => {
                 let total_iter = prefix.iter().chain(slice.iter()).chain(suffix.iter());
-                total_iter.copied().for_each(|p| f(p));
+                total_iter.copied().for_each(&mut f);
             }
             Pat::Record { args, .. } => {
                 args.iter().for_each(|RecordFieldPat { pat, .. }| f(*pat));

crates/hir-def/src/body/lower.rs

@@ -811,7 +811,7 @@ impl ExprCollector<'_> {
                 expr: iterator,
                 arms: Box::new([MatchArm { pat: iter_pat, guard: None, expr: loop_outer }]),
             },
-            syntax_ptr.clone(),
+            syntax_ptr,
         )
     }
 

crates/hir-def/src/body/pretty.rs

@@ -36,7 +36,7 @@ pub(super) fn print_body_hir(db: &dyn DefDatabase, body: &Body, owner: DefWithBo
             let item_tree_id = it.lookup(db).id;
             let name = match &item_tree_id.item_tree(db)[item_tree_id.value].name {
                 Some(name) => name.display(db.upcast()).to_string(),
-                None => "_".to_string(),
+                None => "_".to_owned(),
             };
             format!("const {name} = ")
         }
@@ -45,7 +45,7 @@ pub(super) fn print_body_hir(db: &dyn DefDatabase, body: &Body, owner: DefWithBo
             let variant = &src.value[it.local_id];
             match &variant.name() {
                 Some(name) => name.to_string(),
-                None => "_".to_string(),
+                None => "_".to_owned(),
             }
         }
     };

crates/hir-def/src/data.rs

@@ -739,7 +739,7 @@ impl<'a> AssocItemCollector<'a> {
             self.diagnostics.push(DefDiagnostic::macro_expansion_parse_error(
                 self.module_id.local_id,
                 error_call_kind(),
-                errors.into(),
+                errors,
             ));
         }
 

crates/hir-def/src/data/adt.rs

@@ -473,7 +473,7 @@ fn lower_struct(
     trace: &mut Trace<FieldData, Either<ast::TupleField, ast::RecordField>>,
     ast: &InFile<ast::StructKind>,
 ) -> StructKind {
-    let ctx = LowerCtx::new(db, &expander.hygiene(), ast.file_id);
+    let ctx = LowerCtx::new(db, expander.hygiene(), ast.file_id);
 
     match &ast.value {
         ast::StructKind::Tuple(fl) => {

crates/hir-def/src/db.rs

@@ -193,7 +193,7 @@ pub trait DefDatabase: InternDatabase + ExpandDatabase + Upcast<dyn ExpandDataba
     fn attrs(&self, def: AttrDefId) -> Attrs;
 
     #[salsa::transparent]
-    #[salsa::invoke(AttrsWithOwner::attrs_with_owner)]
+    #[salsa::invoke(AttrsWithOwner::attrs_with_owner_query)]
     fn attrs_with_owner(&self, def: AttrDefId) -> AttrsWithOwner;
 
     // endregion:attrs
@@ -271,10 +271,8 @@ fn crate_supports_no_std(db: &dyn DefDatabase, crate_id: CrateId) -> bool {
             None => continue,
         };
 
-        let segments = tt.split(|tt| match tt {
-            tt::TokenTree::Leaf(tt::Leaf::Punct(p)) if p.char == ',' => true,
-            _ => false,
-        });
+        let segments =
+            tt.split(|tt| matches!(tt, tt::TokenTree::Leaf(tt::Leaf::Punct(p)) if p.char == ','));
         for output in segments.skip(1) {
             match output {
                 [tt::TokenTree::Leaf(tt::Leaf::Ident(ident))] if ident.text == "no_std" => {

crates/hir-def/src/dyn_map.rs

@@ -14,7 +14,7 @@
 //! let mut map = DynMap::new();
 //!
 //! // To access a specific map, index the `DynMap` by `Key`:
-//! map[STRING_TO_U32].insert("hello".to_string(), 92);
+//! map[STRING_TO_U32].insert("hello".to_owned(), 92);
 //! let value = map[U32_TO_VEC].get(92);
 //! assert!(value.is_none());
 //! ```

crates/hir-def/src/find_path.rs

@@ -206,7 +206,7 @@ fn find_path_for_module(
     }
 
     if let value @ Some(_) =
-        find_in_prelude(db, &root_def_map, &def_map, ItemInNs::Types(module_id.into()), from)
+        find_in_prelude(db, &root_def_map, def_map, ItemInNs::Types(module_id.into()), from)
     {
         return value;
     }

crates/hir-def/src/generics.rs

@@ -300,6 +300,7 @@ impl GenericParams {
         }
     }
 
+    #[allow(clippy::borrowed_box)]
     fn add_where_predicate_from_bound(
         &mut self,
         lower_ctx: &LowerCtx<'_>,