Merge branch 'master' into lifetimes_bound_nested_ref

Also add IntegerDivisionRemainderUsed

# Conflicts:
#	clippy_lints/src/lib.rs

Author: Ype Kingma

.github/workflows/clippy.yml

@@ -26,17 +26,19 @@ env:
   NO_FMT_TEST: 1
   CARGO_INCREMENTAL: 0
 
+concurrency:
+  # For a given workflow, if we push to the same PR, cancel all previous builds on that PR.
+  # If the push is not attached to a PR, we will cancel all builds on the same branch.
+  group: "${{ github.workflow }}-${{ github.event.pull_request.number || github.ref }}"
+  cancel-in-progress: true
+
 jobs:
   base:
     # NOTE: If you modify this job, make sure you copy the changes to clippy_bors.yml
     runs-on: ubuntu-latest
 
     steps:
     # Setup
-    - uses: rust-lang/simpleinfra/github-actions/cancel-outdated-builds@master
-      with:
-        github_token: "${{ secrets.github_token }}"
-
     - name: Checkout
       uses: actions/checkout@v4
 

.github/workflows/clippy_bors.yml

@@ -12,6 +12,11 @@ env:
   NO_FMT_TEST: 1
   CARGO_INCREMENTAL: 0
 
+concurrency:
+  # For a given workflow, if we push to the same branch, cancel all previous builds on that branch.
+  group: "${{ github.workflow }}-${{ github.event.pull_request.number || github.ref }}"
+  cancel-in-progress: true
+
 defaults:
   run:
     shell: bash
@@ -21,10 +26,6 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-    - uses: rust-lang/simpleinfra/github-actions/cancel-outdated-builds@master
-      with:
-        github_token: "${{ secrets.github_token }}"
-
     - name: Checkout
       uses: actions/checkout@v4
       with:
@@ -67,10 +68,6 @@ jobs:
     # NOTE: If you modify this job, make sure you copy the changes to clippy.yml
     steps:
     # Setup
-    - uses: rust-lang/simpleinfra/github-actions/cancel-outdated-builds@master
-      with:
-        github_token: "${{ secrets.github_token }}"
-
     - name: Checkout
       uses: actions/checkout@v4
 
@@ -131,10 +128,6 @@ jobs:
 
     steps:
      # Setup
-    - uses: rust-lang/simpleinfra/github-actions/cancel-outdated-builds@master
-      with:
-        github_token: "${{ secrets.github_token }}"
-
     - name: Checkout
       uses: actions/checkout@v4
 
@@ -155,10 +148,6 @@ jobs:
 
     steps:
     # Setup
-    - uses: rust-lang/simpleinfra/github-actions/cancel-outdated-builds@master
-      with:
-        github_token: "${{ secrets.github_token }}"
-
     - name: Checkout
       uses: actions/checkout@v4
 
@@ -211,10 +200,6 @@ jobs:
 
     steps:
     # Setup
-    - uses: rust-lang/simpleinfra/github-actions/cancel-outdated-builds@master
-      with:
-        github_token: "${{ secrets.github_token }}"
-
     - name: Checkout
       uses: actions/checkout@v4
 

CHANGELOG.md

@@ -5157,6 +5157,7 @@ Released 2018-09-13
 [`drop_ref`]: https://rust-lang.github.io/rust-clippy/master/index.html#drop_ref
 [`duplicate_mod`]: https://rust-lang.github.io/rust-clippy/master/index.html#duplicate_mod
 [`duplicate_underscore_argument`]: https://rust-lang.github.io/rust-clippy/master/index.html#duplicate_underscore_argument
+[`duplicated_attributes`]: https://rust-lang.github.io/rust-clippy/master/index.html#duplicated_attributes
 [`duration_subsec`]: https://rust-lang.github.io/rust-clippy/master/index.html#duration_subsec
 [`eager_transmute`]: https://rust-lang.github.io/rust-clippy/master/index.html#eager_transmute
 [`else_if_without_else`]: https://rust-lang.github.io/rust-clippy/master/index.html#else_if_without_else
@@ -5282,6 +5283,7 @@ Released 2018-09-13
 [`int_plus_one`]: https://rust-lang.github.io/rust-clippy/master/index.html#int_plus_one
 [`integer_arithmetic`]: https://rust-lang.github.io/rust-clippy/master/index.html#integer_arithmetic
 [`integer_division`]: https://rust-lang.github.io/rust-clippy/master/index.html#integer_division
+[`integer_division_remainder_used`]: https://rust-lang.github.io/rust-clippy/master/index.html#integer_division_remainder_used
 [`into_iter_on_array`]: https://rust-lang.github.io/rust-clippy/master/index.html#into_iter_on_array
 [`into_iter_on_ref`]: https://rust-lang.github.io/rust-clippy/master/index.html#into_iter_on_ref
 [`into_iter_without_iter`]: https://rust-lang.github.io/rust-clippy/master/index.html#into_iter_without_iter

Cargo.toml

@@ -24,26 +24,26 @@ path = "src/driver.rs"
 clippy_config = { path = "clippy_config" }
 clippy_lints = { path = "clippy_lints" }
 rustc_tools_util = "0.3.0"
-tempfile = { version = "3.2", optional = true }
+tempfile = { version = "3.3", optional = true }
 termize = "0.1"
 color-print = "0.3.4"
 anstream = "0.6.0"
 
 [dev-dependencies]
 ui_test = "0.22.2"
 tester = "0.9"
-regex = "1.5"
+regex = "1.5.5"
 toml = "0.7.3"
 walkdir = "2.3"
 # This is used by the `collect-metadata` alias.
-filetime = "0.2"
+filetime = "0.2.9"
 itertools = "0.12"
 
 # UI test dependencies
 clippy_utils = { path = "clippy_utils" }
 if_chain = "1.0"
-quote = "1.0"
-serde = { version = "1.0.125", features = ["derive"] }
+quote = "1.0.25"
+serde = { version = "1.0.145", features = ["derive"] }
 syn = { version = "2.0", features = ["full"] }
 futures = "0.3"
 parking_lot = "0.12"

book/src/development/macro_expansions.md

@@ -52,7 +52,7 @@ if expr.span.from_expansion() {
 
 ### `Span.ctxt` method
 
-The `span`'s context, given by the method [`ctxt`] and returning [SpanContext],
+The `span`'s context, given by the method [`ctxt`] and returning [SyntaxContext],
 represents if the span is from a macro expansion and, if it is, which
 macro call expanded this span.
 
@@ -155,4 +155,4 @@ if in_external_macro(cx.sess(), foo_span) {
 [`from_expansion`]: https://doc.rust-lang.org/stable/nightly-rustc/rustc_span/struct.Span.html#method.from_expansion
 [`in_external_macro`]: https://doc.rust-lang.org/stable/nightly-rustc/rustc_middle/lint/fn.in_external_macro.html
 [Span]: https://doc.rust-lang.org/stable/nightly-rustc/rustc_span/struct.Span.html
-[SpanContext]: https://doc.rust-lang.org/stable/nightly-rustc/rustc_span/hygiene/struct.SyntaxContext.html
+[SyntaxContext]: https://doc.rust-lang.org/stable/nightly-rustc/rustc_span/hygiene/struct.SyntaxContext.html

clippy_dev/src/update_lints.rs

@@ -689,6 +689,8 @@ fn gen_deprecated_lints_test(lints: &[DeprecatedLint]) -> String {
 fn gen_renamed_lints_test(lints: &[RenamedLint]) -> String {
     let mut seen_lints = HashSet::new();
     let mut res: String = GENERATED_FILE_COMMENT.into();
+
+    res.push_str("#![allow(clippy::duplicated_attributes)]\n");
     for lint in lints {
         if seen_lints.insert(&lint.new_name) {
             writeln!(res, "#![allow({})]", lint.new_name).unwrap();

clippy_lints/src/attrs/duplicated_attributes.rs

@@ -0,0 +1,64 @@
+use super::DUPLICATED_ATTRIBUTES;
+use clippy_utils::diagnostics::span_lint_and_then;
+use rustc_ast::{Attribute, MetaItem};
+use rustc_data_structures::fx::FxHashMap;
+use rustc_lint::EarlyContext;
+use rustc_span::{sym, Span};
+use std::collections::hash_map::Entry;
+
+fn emit_if_duplicated(
+    cx: &EarlyContext<'_>,
+    attr: &MetaItem,
+    attr_paths: &mut FxHashMap<String, Span>,
+    complete_path: String,
+) {
+    match attr_paths.entry(complete_path) {
+        Entry::Vacant(v) => {
+            v.insert(attr.span);
+        },
+        Entry::Occupied(o) => {
+            span_lint_and_then(cx, DUPLICATED_ATTRIBUTES, attr.span, "duplicated attribute", |diag| {
+                diag.span_note(*o.get(), "first defined here");
+                diag.span_help(attr.span, "remove this attribute");
+            });
+        },
+    }
+}
+
+fn check_duplicated_attr(
+    cx: &EarlyContext<'_>,
+    attr: &MetaItem,
+    attr_paths: &mut FxHashMap<String, Span>,
+    parent: &mut Vec<String>,
+) {
+    let Some(ident) = attr.ident() else { return };
+    let name = ident.name;
+    if name == sym::doc || name == sym::cfg_attr {
+        // FIXME: Would be nice to handle `cfg_attr` as well. Only problem is to check that cfg
+        // conditions are the same.
+        return;
+    }
+    if let Some(value) = attr.value_str() {
+        emit_if_duplicated(cx, attr, attr_paths, format!("{}:{name}={value}", parent.join(":")));
+    } else if let Some(sub_attrs) = attr.meta_item_list() {
+        parent.push(name.as_str().to_string());
+        for sub_attr in sub_attrs {
+            if let Some(meta) = sub_attr.meta_item() {
+                check_duplicated_attr(cx, meta, attr_paths, parent);
+            }
+        }
+        parent.pop();
+    } else {
+        emit_if_duplicated(cx, attr, attr_paths, format!("{}:{name}", parent.join(":")));
+    }
+}
+
+pub fn check(cx: &EarlyContext<'_>, attrs: &[Attribute]) {
+    let mut attr_paths = FxHashMap::default();
+
+    for attr in attrs {
+        if let Some(meta) = attr.meta() {
+            check_duplicated_attr(cx, &meta, &mut attr_paths, &mut Vec::new());
+        }
+    }
+}

clippy_lints/src/attrs/mod.rs

@@ -4,6 +4,7 @@ mod allow_attributes_without_reason;
 mod blanket_clippy_restriction_lints;
 mod deprecated_cfg_attr;
 mod deprecated_semver;
+mod duplicated_attributes;
 mod empty_line_after;
 mod inline_always;
 mod maybe_misused_cfg;
@@ -16,7 +17,7 @@ mod useless_attribute;
 mod utils;
 
 use clippy_config::msrvs::Msrv;
-use rustc_ast::{Attribute, MetaItemKind, NestedMetaItem};
+use rustc_ast::{Attribute, Crate, MetaItemKind, NestedMetaItem};
 use rustc_hir::{ImplItem, Item, ItemKind, TraitItem};
 use rustc_lint::{EarlyContext, EarlyLintPass, LateContext, LateLintPass};
 use rustc_session::{declare_lint_pass, impl_lint_pass};
@@ -489,6 +490,32 @@ declare_clippy_lint! {
     "item has both inner and outer attributes"
 }
 
+declare_clippy_lint! {
+    /// ### What it does
+    /// Checks for attributes that appear two or more times.
+    ///
+    /// ### Why is this bad?
+    /// Repeating an attribute on the same item (or globally on the same crate)
+    /// is unnecessary and doesn't have an effect.
+    ///
+    /// ### Example
+    /// ```no_run
+    /// #[allow(dead_code)]
+    /// #[allow(dead_code)]
+    /// fn foo() {}
+    /// ```
+    ///
+    /// Use instead:
+    /// ```no_run
+    /// #[allow(dead_code)]
+    /// fn foo() {}
+    /// ```
+    #[clippy::version = "1.78.0"]
+    pub DUPLICATED_ATTRIBUTES,
+    suspicious,
+    "duplicated attribute"
+}
+
 declare_lint_pass!(Attributes => [
     ALLOW_ATTRIBUTES_WITHOUT_REASON,
     INLINE_ALWAYS,
@@ -568,12 +595,18 @@ impl_lint_pass!(EarlyAttributes => [
     DEPRECATED_CLIPPY_CFG_ATTR,
     UNNECESSARY_CLIPPY_CFG,
     MIXED_ATTRIBUTES_STYLE,
+    DUPLICATED_ATTRIBUTES,
 ]);
 
 impl EarlyLintPass for EarlyAttributes {
+    fn check_crate(&mut self, cx: &EarlyContext<'_>, krate: &Crate) {
+        duplicated_attributes::check(cx, &krate.attrs);
+    }
+
     fn check_item(&mut self, cx: &EarlyContext<'_>, item: &rustc_ast::Item) {
         empty_line_after::check(cx, item);
         mixed_attributes_style::check(cx, item);
+        duplicated_attributes::check(cx, &item.attrs);
     }
 
     fn check_attribute(&mut self, cx: &EarlyContext<'_>, attr: &Attribute) {

clippy_lints/src/casts/cast_lossless.rs

@@ -1,10 +1,10 @@
 use clippy_config::msrvs::{self, Msrv};
 use clippy_utils::diagnostics::span_lint_and_sugg;
 use clippy_utils::in_constant;
-use clippy_utils::source::snippet_opt;
+use clippy_utils::source::{snippet_opt, snippet_with_applicability};
 use clippy_utils::ty::is_isize_or_usize;
 use rustc_errors::Applicability;
-use rustc_hir::{Expr, ExprKind};
+use rustc_hir::{Expr, ExprKind, QPath, TyKind};
 use rustc_lint::LateContext;
 use rustc_middle::ty::{self, FloatTy, Ty};
 
@@ -16,6 +16,7 @@ pub(super) fn check(
     cast_op: &Expr<'_>,
     cast_from: Ty<'_>,
     cast_to: Ty<'_>,
+    cast_to_hir: &rustc_hir::Ty<'_>,
     msrv: &Msrv,
 ) {
     if !should_lint(cx, expr, cast_from, cast_to, msrv) {
@@ -24,11 +25,11 @@ pub(super) fn check(
 
     // The suggestion is to use a function call, so if the original expression
     // has parens on the outside, they are no longer needed.
-    let mut applicability = Applicability::MachineApplicable;
+    let mut app = Applicability::MachineApplicable;
     let opt = snippet_opt(cx, cast_op.span.source_callsite());
     let sugg = opt.as_ref().map_or_else(
         || {
-            applicability = Applicability::HasPlaceholders;
+            app = Applicability::HasPlaceholders;
             ".."
         },
         |snip| {
@@ -40,10 +41,27 @@ pub(super) fn check(
         },
     );
 
+    // Display the type alias instead of the aliased type. Fixes #11285
+    //
+    // FIXME: Once `lazy_type_alias` is stabilized(?) we should use `rustc_middle` types instead,
+    // this will allow us to display the right type with `cast_from` as well.
+    let cast_to_fmt = if let TyKind::Path(QPath::Resolved(None, path)) = cast_to_hir.kind
+        // It's a bit annoying but the turbofish is optional for types. A type in an `as` cast
+        // shouldn't have these if they're primitives, which are the only things we deal with.
+        //
+        // This could be removed for performance if this check is determined to have a pretty major
+        // effect.
+        && path.segments.iter().all(|segment| segment.args.is_none())
+    {
+        snippet_with_applicability(cx, cast_to_hir.span, "..", &mut app)
+    } else {
+        cast_to.to_string().into()
+    };
+
     let message = if cast_from.is_bool() {
-        format!("casting `{cast_from:}` to `{cast_to:}` is more cleanly stated with `{cast_to:}::from(_)`")
+        format!("casting `{cast_from}` to `{cast_to_fmt}` is more cleanly stated with `{cast_to_fmt}::from(_)`")
     } else {
-        format!("casting `{cast_from}` to `{cast_to}` may become silently lossy if you later change the type")
+        format!("casting `{cast_from}` to `{cast_to_fmt}` may become silently lossy if you later change the type")
     };
 
     span_lint_and_sugg(
@@ -52,8 +70,8 @@ pub(super) fn check(
         expr.span,
         &message,
         "try",
-        format!("{cast_to}::from({sugg})"),
-        applicability,
+        format!("{cast_to_fmt}::from({sugg})"),
+        app,
     );
 }
 

clippy_lints/src/casts/mod.rs

@@ -791,7 +791,7 @@ impl<'tcx> LateLintPass<'tcx> for Casts {
                     cast_abs_to_unsigned::check(cx, expr, cast_expr, cast_from, cast_to, &self.msrv);
                     cast_nan_to_int::check(cx, expr, cast_expr, cast_from, cast_to);
                 }
-                cast_lossless::check(cx, expr, cast_expr, cast_from, cast_to, &self.msrv);
+                cast_lossless::check(cx, expr, cast_expr, cast_from, cast_to, cast_to_hir, &self.msrv);
                 cast_enum_constructor::check(cx, expr, cast_expr, cast_from);
             }