Merge commit '7f27e2e74ef957baa382dc05cf08df6368165c74' into clippyup

.github/driver.sh

@@ -17,6 +17,13 @@ test "$sysroot" = $desired_sysroot
 sysroot=$(SYSROOT=$desired_sysroot ./target/debug/clippy-driver --print sysroot)
 test "$sysroot" = $desired_sysroot
 
+# Check that the --sysroot argument is only passed once (SYSROOT is ignored)
+(
+    cd rustc_tools_util
+    touch src/lib.rs
+    SYSROOT=/tmp RUSTFLAGS="--sysroot=$(rustc --print sysroot)" ../target/debug/cargo-clippy clippy --verbose
+)
+
 # Make sure this isn't set - clippy-driver should cope without it
 unset CARGO_MANIFEST_DIR
 

CHANGELOG.md

@@ -4137,6 +4137,7 @@ Released 2018-09-13
 [`derive_hash_xor_eq`]: https://rust-lang.github.io/rust-clippy/master/index.html#derive_hash_xor_eq
 [`derive_ord_xor_partial_ord`]: https://rust-lang.github.io/rust-clippy/master/index.html#derive_ord_xor_partial_ord
 [`derive_partial_eq_without_eq`]: https://rust-lang.github.io/rust-clippy/master/index.html#derive_partial_eq_without_eq
+[`derived_hash_with_manual_eq`]: https://rust-lang.github.io/rust-clippy/master/index.html#derived_hash_with_manual_eq
 [`disallowed_macros`]: https://rust-lang.github.io/rust-clippy/master/index.html#disallowed_macros
 [`disallowed_method`]: https://rust-lang.github.io/rust-clippy/master/index.html#disallowed_method
 [`disallowed_methods`]: https://rust-lang.github.io/rust-clippy/master/index.html#disallowed_methods

book/src/installation.md

@@ -1,6 +1,6 @@
 # Installation
 
-If you're using `rustup` to install and manage you're Rust toolchains, Clippy is
+If you're using `rustup` to install and manage your Rust toolchains, Clippy is
 usually **already installed**. In that case you can skip this chapter and go to
 the [Usage] chapter.
 

clippy_dev/src/lib.rs

@@ -5,6 +5,9 @@
 // warn on lints, that are included in `rust-lang/rust`s bootstrap
 #![warn(rust_2018_idioms, unused_lifetimes)]
 
+// The `rustc_driver` crate seems to be required in order to use the `rust_lexer` crate.
+#[allow(unused_extern_crates)]
+extern crate rustc_driver;
 extern crate rustc_lexer;
 
 use std::path::PathBuf;

clippy_lints/src/box_default.rs

@@ -8,7 +8,7 @@ use rustc_hir::{
     Block, Expr, ExprKind, Local, Node, QPath, TyKind,
 };
 use rustc_lint::{LateContext, LateLintPass, LintContext};
-use rustc_middle::lint::in_external_macro;
+use rustc_middle::{lint::in_external_macro, ty::print::with_forced_trimmed_paths};
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 use rustc_span::sym;
 
@@ -59,7 +59,7 @@ impl LateLintPass<'_> for BoxDefault {
                 if is_plain_default(arg_path) || given_type(cx, expr) {
                     "Box::default()".into()
                 } else {
-                    format!("Box::<{arg_ty}>::default()")
+                    with_forced_trimmed_paths!(format!("Box::<{arg_ty}>::default()"))
                 },
                 Applicability::MachineApplicable
             );

clippy_lints/src/copies.rs

@@ -525,7 +525,11 @@ fn check_for_warn_of_moved_symbol(cx: &LateContext<'_>, symbols: &[(HirId, Symbo
             .iter()
             .filter(|&&(_, name)| !name.as_str().starts_with('_'))
             .any(|&(_, name)| {
-                let mut walker = ContainsName { name, result: false };
+                let mut walker = ContainsName {
+                    name,
+                    result: false,
+                    cx,
+                };
 
                 // Scan block
                 block

clippy_lints/src/dbg_macro.rs

@@ -10,11 +10,11 @@ use rustc_span::sym;
 
 declare_clippy_lint! {
     /// ### What it does
-    /// Checks for usage of dbg!() macro.
+    /// Checks for usage of the [`dbg!`](https://doc.rust-lang.org/std/macro.dbg.html) macro.
     ///
     /// ### Why is this bad?
-    /// `dbg!` macro is intended as a debugging tool. It
-    /// should not be in version control.
+    /// The `dbg!` macro is intended as a debugging tool. It should not be present in released
+    /// software or committed to a version control system.
     ///
     /// ### Example
     /// ```rust,ignore
@@ -91,8 +91,8 @@ impl LateLintPass<'_> for DbgMacro {
                 cx,
                 DBG_MACRO,
                 macro_call.span,
-                "`dbg!` macro is intended as a debugging tool",
-                "ensure to avoid having uses of it in version control",
+                "the `dbg!` macro is intended as a debugging tool",
+                "remove the invocation before committing it to a version control system",
                 suggestion,
                 applicability,
             );

clippy_lints/src/declared_lints.rs

@@ -111,7 +111,7 @@ pub(crate) static LINTS: &[&crate::LintInfo] = &[
     crate::dereference::NEEDLESS_BORROW_INFO,
     crate::dereference::REF_BINDING_TO_REFERENCE_INFO,
     crate::derivable_impls::DERIVABLE_IMPLS_INFO,
-    crate::derive::DERIVE_HASH_XOR_EQ_INFO,
+    crate::derive::DERIVED_HASH_WITH_MANUAL_EQ_INFO,
     crate::derive::DERIVE_ORD_XOR_PARTIAL_ORD_INFO,
     crate::derive::DERIVE_PARTIAL_EQ_WITHOUT_EQ_INFO,
     crate::derive::EXPL_IMPL_CLONE_ON_COPY_INFO,

clippy_lints/src/default.rs

@@ -11,6 +11,7 @@ use rustc_hir::def::Res;
 use rustc_hir::{Block, Expr, ExprKind, PatKind, QPath, Stmt, StmtKind};
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_middle::ty;
+use rustc_middle::ty::print::with_forced_trimmed_paths;
 use rustc_session::{declare_tool_lint, impl_lint_pass};
 use rustc_span::symbol::{Ident, Symbol};
 use rustc_span::Span;
@@ -98,9 +99,7 @@ impl<'tcx> LateLintPass<'tcx> for Default {
             if let ty::Adt(def, ..) = expr_ty.kind();
             if !is_from_proc_macro(cx, expr);
             then {
-                // TODO: Work out a way to put "whatever the imported way of referencing
-                // this type in this file" rather than a fully-qualified type.
-                let replacement = format!("{}::default()", cx.tcx.def_path_str(def.did()));
+                let replacement = with_forced_trimmed_paths!(format!("{}::default()", cx.tcx.def_path_str(def.did())));
                 span_lint_and_sugg(
                     cx,
                     DEFAULT_TRAIT_ACCESS,
@@ -170,7 +169,7 @@ impl<'tcx> LateLintPass<'tcx> for Default {
                 // find out if and which field was set by this `consecutive_statement`
                 if let Some((field_ident, assign_rhs)) = field_reassigned_by_stmt(consecutive_statement, binding_name) {
                     // interrupt and cancel lint if assign_rhs references the original binding
-                    if contains_name(binding_name, assign_rhs) {
+                    if contains_name(binding_name, assign_rhs, cx) {
                         cancel_lint = true;
                         break;
                     }

clippy_lints/src/dereference.rs

@@ -1282,10 +1282,10 @@ fn referent_used_exactly_once<'tcx>(
             possible_borrowers.push((body_owner_local_def_id, PossibleBorrowerMap::new(cx, mir)));
         }
         let possible_borrower = &mut possible_borrowers.last_mut().unwrap().1;
-        // If `place.local` were not included here, the `copyable_iterator::warn` test would fail. The
-        // reason is that `PossibleBorrowerVisitor::visit_terminator` considers `place.local` a possible
-        // borrower of itself. See the comment in that method for an explanation as to why.
-        possible_borrower.at_most_borrowers(cx, &[local, place.local], place.local, location)
+        // If `only_borrowers` were used here, the `copyable_iterator::warn` test would fail. The reason is
+        // that `PossibleBorrowerVisitor::visit_terminator` considers `place.local` a possible borrower of
+        // itself. See the comment in that method for an explanation as to why.
+        possible_borrower.bounded_borrowers(&[local], &[local, place.local], place.local, location)
             && used_exactly_once(mir, place.local).unwrap_or(false)
     } else {
         false

clippy_lints/src/derivable_impls.rs

@@ -1,12 +1,15 @@
 use clippy_utils::diagnostics::span_lint_and_then;
+use clippy_utils::msrvs::{self, Msrv};
+use clippy_utils::source::indent_of;
 use clippy_utils::{is_default_equivalent, peel_blocks};
 use rustc_errors::Applicability;
 use rustc_hir::{
-    def::{DefKind, Res},
-    Body, Expr, ExprKind, GenericArg, Impl, ImplItemKind, Item, ItemKind, Node, PathSegment, QPath, TyKind,
+    def::{CtorKind, CtorOf, DefKind, Res},
+    Body, Expr, ExprKind, GenericArg, Impl, ImplItemKind, Item, ItemKind, Node, PathSegment, QPath, Ty, TyKind,
 };
 use rustc_lint::{LateContext, LateLintPass};
-use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_middle::ty::{AdtDef, DefIdTree};
+use rustc_session::{declare_tool_lint, impl_lint_pass};
 use rustc_span::sym;
 
 declare_clippy_lint! {
@@ -51,7 +54,18 @@ declare_clippy_lint! {
     "manual implementation of the `Default` trait which is equal to a derive"
 }
 
-declare_lint_pass!(DerivableImpls => [DERIVABLE_IMPLS]);
+pub struct DerivableImpls {
+    msrv: Msrv,
+}
+
+impl DerivableImpls {
+    #[must_use]
+    pub fn new(msrv: Msrv) -> Self {
+        DerivableImpls { msrv }
+    }
+}
+
+impl_lint_pass!(DerivableImpls => [DERIVABLE_IMPLS]);
 
 fn is_path_self(e: &Expr<'_>) -> bool {
     if let ExprKind::Path(QPath::Resolved(_, p)) = e.kind {
@@ -61,6 +75,98 @@ fn is_path_self(e: &Expr<'_>) -> bool {
     }
 }
 
+fn check_struct<'tcx>(
+    cx: &LateContext<'tcx>,
+    item: &'tcx Item<'_>,
+    self_ty: &Ty<'_>,
+    func_expr: &Expr<'_>,
+    adt_def: AdtDef<'_>,
+) {
+    if let TyKind::Path(QPath::Resolved(_, p)) = self_ty.kind {
+        if let Some(PathSegment { args: Some(a), .. }) = p.segments.last() {
+            for arg in a.args {
+                if !matches!(arg, GenericArg::Lifetime(_)) {
+                    return;
+                }
+            }
+        }
+    }
+    let should_emit = match peel_blocks(func_expr).kind {
+        ExprKind::Tup(fields) => fields.iter().all(|e| is_default_equivalent(cx, e)),
+        ExprKind::Call(callee, args) if is_path_self(callee) => args.iter().all(|e| is_default_equivalent(cx, e)),
+        ExprKind::Struct(_, fields, _) => fields.iter().all(|ef| is_default_equivalent(cx, ef.expr)),
+        _ => false,
+    };
+
+    if should_emit {
+        let struct_span = cx.tcx.def_span(adt_def.did());
+        span_lint_and_then(cx, DERIVABLE_IMPLS, item.span, "this `impl` can be derived", |diag| {
+            diag.span_suggestion_hidden(
+                item.span,
+                "remove the manual implementation...",
+                String::new(),
+                Applicability::MachineApplicable,
+            );
+            diag.span_suggestion(
+                struct_span.shrink_to_lo(),
+                "...and instead derive it",
+                "#[derive(Default)]\n".to_string(),
+                Applicability::MachineApplicable,
+            );
+        });
+    }
+}
+
+fn check_enum<'tcx>(cx: &LateContext<'tcx>, item: &'tcx Item<'_>, func_expr: &Expr<'_>, adt_def: AdtDef<'_>) {
+    if_chain! {
+        if let ExprKind::Path(QPath::Resolved(None, p)) = &peel_blocks(func_expr).kind;
+        if let Res::Def(DefKind::Ctor(CtorOf::Variant, CtorKind::Const), id) = p.res;
+        if let variant_id = cx.tcx.parent(id);
+        if let Some(variant_def) = adt_def.variants().iter().find(|v| v.def_id == variant_id);
+        if variant_def.fields.is_empty();
+        if !variant_def.is_field_list_non_exhaustive();
+
+        then {
+            let enum_span = cx.tcx.def_span(adt_def.did());
+            let indent_enum = indent_of(cx, enum_span).unwrap_or(0);
+            let variant_span = cx.tcx.def_span(variant_def.def_id);
+            let indent_variant = indent_of(cx, variant_span).unwrap_or(0);
+            span_lint_and_then(
+                cx,
+                DERIVABLE_IMPLS,
+                item.span,
+                "this `impl` can be derived",
+                |diag| {
+                    diag.span_suggestion_hidden(
+                        item.span,
+                        "remove the manual implementation...",
+                        String::new(),
+                        Applicability::MachineApplicable
+                    );
+                    diag.span_suggestion(
+                        enum_span.shrink_to_lo(),
+                        "...and instead derive it...",
+                        format!(
+                            "#[derive(Default)]\n{indent}",
+                            indent = " ".repeat(indent_enum),
+                        ),
+                        Applicability::MachineApplicable
+                    );
+                    diag.span_suggestion(
+                        variant_span.shrink_to_lo(),
+                        "...and mark the default variant",
+                        format!(
+                            "#[default]\n{indent}",
+                            indent = " ".repeat(indent_variant),
+                        ),
+                        Applicability::MachineApplicable
+                    );
+                }
+            );
+        }
+    }
+}
+
 impl<'tcx> LateLintPass<'tcx> for DerivableImpls {
     fn check_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx Item<'_>) {
         if_chain! {
@@ -83,49 +189,16 @@ impl<'tcx> LateLintPass<'tcx> for DerivableImpls {
             if !attrs.iter().any(|attr| attr.doc_str().is_some());
             if let child_attrs = cx.tcx.hir().attrs(impl_item_hir);
             if !child_attrs.iter().any(|attr| attr.doc_str().is_some());
-            if adt_def.is_struct();
-            then {
-                if let TyKind::Path(QPath::Resolved(_, p)) = self_ty.kind {
-                    if let Some(PathSegment { args: Some(a), .. }) = p.segments.last() {
-                        for arg in a.args {
-                            if !matches!(arg, GenericArg::Lifetime(_)) {
-                                return;
-                            }
-                        }
-                    }
-                }
-                let should_emit = match peel_blocks(func_expr).kind {
-                    ExprKind::Tup(fields) => fields.iter().all(|e| is_default_equivalent(cx, e)),
-                    ExprKind::Call(callee, args)
-                        if is_path_self(callee) => args.iter().all(|e| is_default_equivalent(cx, e)),
-                    ExprKind::Struct(_, fields, _) => fields.iter().all(|ef| is_default_equivalent(cx, ef.expr)),
-                    _ => false,
-                };
 
-                if should_emit {
-                    let struct_span = cx.tcx.def_span(adt_def.did());
-                    span_lint_and_then(
-                        cx,
-                        DERIVABLE_IMPLS,
-                        item.span,
-                        "this `impl` can be derived",
-                        |diag| {
-                            diag.span_suggestion_hidden(
-                                item.span,
-                                "remove the manual implementation...",
-                                String::new(),
-                                Applicability::MachineApplicable
-                            );
-                            diag.span_suggestion(
-                                struct_span.shrink_to_lo(),
-                                "...and instead derive it",
-                                "#[derive(Default)]\n".to_string(),
-                                Applicability::MachineApplicable
-                            );
-                        }
-                    );
+            then {
+                if adt_def.is_struct() {
+                    check_struct(cx, item, self_ty, func_expr, adt_def);
+                } else if adt_def.is_enum() && self.msrv.meets(msrvs::DEFAULT_ENUM_ATTRIBUTE) {
+                    check_enum(cx, item, func_expr, adt_def);
                 }
             }
         }
     }
+
+    extract_msrv_attr!(LateContext);
 }