Merge commit 'ac0e10aa68325235069a842f47499852b2dee79e' into clippyup

13 files changed, 74 insertions, 76 deletions

diff --git a/clippy_lints/src/casts/borrow_as_ptr.rs b/clippy_lints/src/casts/borrow_as_ptr.rs
index 6e1f8cd64f0..294d22d34de 100644
--- a/clippy_lints/src/casts/borrow_as_ptr.rs
+++ b/clippy_lints/src/casts/borrow_as_ptr.rs
@@ -30,7 +30,7 @@ pub(super) fn check<'tcx>(
             expr.span,
             "borrow as raw pointer",
             "try",
-            format!("{}::ptr::{}!({})", core_or_std, macro_name, snip),
+            format!("{core_or_std}::ptr::{macro_name}!({snip})"),
             Applicability::MachineApplicable,
         );
     }
diff --git a/clippy_lints/src/casts/cast_lossless.rs b/clippy_lints/src/casts/cast_lossless.rs
index 938458e30ca..13c403234da 100644
--- a/clippy_lints/src/casts/cast_lossless.rs
+++ b/clippy_lints/src/casts/cast_lossless.rs
@@ -41,15 +41,9 @@ pub(super) fn check(
     );
 
     let message = if cast_from.is_bool() {
-        format!(
-            "casting `{0:}` to `{1:}` is more cleanly stated with `{1:}::from(_)`",
-            cast_from, cast_to
-        )
+        format!("casting `{cast_from:}` to `{cast_to:}` is more cleanly stated with `{cast_to:}::from(_)`")
     } else {
-        format!(
-            "casting `{}` to `{}` may become silently lossy if you later change the type",
-            cast_from, cast_to
-        )
+        format!("casting `{cast_from}` to `{cast_to}` may become silently lossy if you later change the type")
     };
 
     span_lint_and_sugg(
@@ -58,7 +52,7 @@ pub(super) fn check(
         expr.span,
         &message,
         "try",
-        format!("{}::from({})", cast_to, sugg),
+        format!("{cast_to}::from({sugg})"),
         applicability,
     );
 }
diff --git a/clippy_lints/src/casts/cast_possible_truncation.rs b/clippy_lints/src/casts/cast_possible_truncation.rs
index 406547a4454..88deb4565eb 100644
--- a/clippy_lints/src/casts/cast_possible_truncation.rs
+++ b/clippy_lints/src/casts/cast_possible_truncation.rs
@@ -103,10 +103,7 @@ pub(super) fn check(cx: &LateContext<'_>, expr: &Expr<'_>, cast_expr: &Expr<'_>,
                 return;
             }
 
-            format!(
-                "casting `{}` to `{}` may truncate the value{}",
-                cast_from, cast_to, suffix,
-            )
+            format!("casting `{cast_from}` to `{cast_to}` may truncate the value{suffix}",)
         },
 
         (ty::Adt(def, _), true) if def.is_enum() => {
@@ -142,20 +139,17 @@ pub(super) fn check(cx: &LateContext<'_>, expr: &Expr<'_>, cast_expr: &Expr<'_>,
                     CAST_ENUM_TRUNCATION,
                     expr.span,
                     &format!(
-                        "casting `{}::{}` to `{}` will truncate the value{}",
-                        cast_from, variant.name, cast_to, suffix,
+                        "casting `{cast_from}::{}` to `{cast_to}` will truncate the value{suffix}",
+                        variant.name,
                     ),
                 );
                 return;
             }
-            format!(
-                "casting `{}` to `{}` may truncate the value{}",
-                cast_from, cast_to, suffix,
-            )
+            format!("casting `{cast_from}` to `{cast_to}` may truncate the value{suffix}",)
         },
 
         (ty::Float(_), true) => {
-            format!("casting `{}` to `{}` may truncate the value", cast_from, cast_to)
+            format!("casting `{cast_from}` to `{cast_to}` may truncate the value")
         },
 
         (ty::Float(FloatTy::F64), false) if matches!(cast_to.kind(), &ty::Float(FloatTy::F32)) => {
diff --git a/clippy_lints/src/casts/cast_possible_wrap.rs b/clippy_lints/src/casts/cast_possible_wrap.rs
index 2c5c1d7cb46..28ecdea7ea0 100644
--- a/clippy_lints/src/casts/cast_possible_wrap.rs
+++ b/clippy_lints/src/casts/cast_possible_wrap.rs
@@ -35,10 +35,7 @@ pub(super) fn check(cx: &LateContext<'_>, expr: &Expr<'_>, cast_from: Ty<'_>, ca
             cx,
             CAST_POSSIBLE_WRAP,
             expr.span,
-            &format!(
-                "casting `{}` to `{}` may wrap around the value{}",
-                cast_from, cast_to, suffix,
-            ),
+            &format!("casting `{cast_from}` to `{cast_to}` may wrap around the value{suffix}",),
         );
     }
 }
diff --git a/clippy_lints/src/casts/cast_ptr_alignment.rs b/clippy_lints/src/casts/cast_ptr_alignment.rs
index da7b12f6726..97054a0d101 100644
--- a/clippy_lints/src/casts/cast_ptr_alignment.rs
+++ b/clippy_lints/src/casts/cast_ptr_alignment.rs
@@ -49,9 +49,7 @@ fn lint_cast_ptr_alignment<'tcx>(cx: &LateContext<'tcx>, expr: &Expr<'_>, cast_f
             CAST_PTR_ALIGNMENT,
             expr.span,
             &format!(
-                "casting from `{}` to a more-strictly-aligned pointer (`{}`) ({} < {} bytes)",
-                cast_from,
-                cast_to,
+                "casting from `{cast_from}` to a more-strictly-aligned pointer (`{cast_to}`) ({} < {} bytes)",
                 from_layout.align.abi.bytes(),
                 to_layout.align.abi.bytes(),
             ),
diff --git a/clippy_lints/src/casts/cast_sign_loss.rs b/clippy_lints/src/casts/cast_sign_loss.rs
index 5b59350be04..a20a97d4e56 100644
--- a/clippy_lints/src/casts/cast_sign_loss.rs
+++ b/clippy_lints/src/casts/cast_sign_loss.rs
@@ -14,10 +14,7 @@ pub(super) fn check(cx: &LateContext<'_>, expr: &Expr<'_>, cast_op: &Expr<'_>, c
             cx,
             CAST_SIGN_LOSS,
             expr.span,
-            &format!(
-                "casting `{}` to `{}` may lose the sign of the value",
-                cast_from, cast_to
-            ),
+            &format!("casting `{cast_from}` to `{cast_to}` may lose the sign of the value"),
         );
     }
 }
diff --git a/clippy_lints/src/casts/cast_slice_different_sizes.rs b/clippy_lints/src/casts/cast_slice_different_sizes.rs
index 027c660ce3b..d31d10d22b9 100644
--- a/clippy_lints/src/casts/cast_slice_different_sizes.rs
+++ b/clippy_lints/src/casts/cast_slice_different_sizes.rs
@@ -35,8 +35,8 @@ pub(super) fn check<'tcx>(cx: &LateContext<'tcx>, expr: &Expr<'tcx>, msrv: Optio
                     CAST_SLICE_DIFFERENT_SIZES,
                     expr.span,
                     &format!(
-                        "casting between raw pointers to `[{}]` (element size {}) and `[{}]` (element size {}) does not adjust the count",
-                        start_ty.ty, from_size, end_ty.ty, to_size,
+                        "casting between raw pointers to `[{}]` (element size {from_size}) and `[{}]` (element size {to_size}) does not adjust the count",
+                        start_ty.ty, end_ty.ty,
                     ),
                     |diag| {
                         let ptr_snippet = source::snippet(cx, left_cast.span, "..");
diff --git a/clippy_lints/src/casts/char_lit_as_u8.rs b/clippy_lints/src/casts/char_lit_as_u8.rs
index 7cc406018db..82e07c98a7e 100644
--- a/clippy_lints/src/casts/char_lit_as_u8.rs
+++ b/clippy_lints/src/casts/char_lit_as_u8.rs
@@ -31,7 +31,7 @@ pub(super) fn check(cx: &LateContext<'_>, expr: &Expr<'_>) {
                         diag.span_suggestion(
                             expr.span,
                             "use a byte literal instead",
-                            format!("b{}", snippet),
+                            format!("b{snippet}"),
                             applicability,
                         );
                     }
diff --git a/clippy_lints/src/casts/fn_to_numeric_cast.rs b/clippy_lints/src/casts/fn_to_numeric_cast.rs
index 35350d8a25b..a26bfab4e7c 100644
--- a/clippy_lints/src/casts/fn_to_numeric_cast.rs
+++ b/clippy_lints/src/casts/fn_to_numeric_cast.rs
@@ -25,9 +25,9 @@ pub(super) fn check(cx: &LateContext<'_>, expr: &Expr<'_>, cast_expr: &Expr<'_>,
                     cx,
                     FN_TO_NUMERIC_CAST,
                     expr.span,
-                    &format!("casting function pointer `{}` to `{}`", from_snippet, cast_to),
+                    &format!("casting function pointer `{from_snippet}` to `{cast_to}`"),
                     "try",
-                    format!("{} as usize", from_snippet),
+                    format!("{from_snippet} as usize"),
                     applicability,
                 );
             }
diff --git a/clippy_lints/src/casts/fn_to_numeric_cast_any.rs b/clippy_lints/src/casts/fn_to_numeric_cast_any.rs
index 03621887a34..75654129408 100644
--- a/clippy_lints/src/casts/fn_to_numeric_cast_any.rs
+++ b/clippy_lints/src/casts/fn_to_numeric_cast_any.rs
@@ -23,9 +23,9 @@ pub(super) fn check(cx: &LateContext<'_>, expr: &Expr<'_>, cast_expr: &Expr<'_>,
                 cx,
                 FN_TO_NUMERIC_CAST_ANY,
                 expr.span,
-                &format!("casting function pointer `{}` to `{}`", from_snippet, cast_to),
+                &format!("casting function pointer `{from_snippet}` to `{cast_to}`"),
                 "did you mean to invoke the function?",
-                format!("{}() as {}", from_snippet, cast_to),
+                format!("{from_snippet}() as {cast_to}"),
                 applicability,
             );
         },
diff --git a/clippy_lints/src/casts/fn_to_numeric_cast_with_truncation.rs b/clippy_lints/src/casts/fn_to_numeric_cast_with_truncation.rs
index 6287f479b5b..556be1d1506 100644
--- a/clippy_lints/src/casts/fn_to_numeric_cast_with_truncation.rs
+++ b/clippy_lints/src/casts/fn_to_numeric_cast_with_truncation.rs
@@ -24,12 +24,9 @@ pub(super) fn check(cx: &LateContext<'_>, expr: &Expr<'_>, cast_expr: &Expr<'_>,
                     cx,
                     FN_TO_NUMERIC_CAST_WITH_TRUNCATION,
                     expr.span,
-                    &format!(
-                        "casting function pointer `{}` to `{}`, which truncates the value",
-                        from_snippet, cast_to
-                    ),
+                    &format!("casting function pointer `{from_snippet}` to `{cast_to}`, which truncates the value"),
                     "try",
-                    format!("{} as usize", from_snippet),
+                    format!("{from_snippet} as usize"),
                     applicability,
                 );
             }
diff --git a/clippy_lints/src/casts/ptr_as_ptr.rs b/clippy_lints/src/casts/ptr_as_ptr.rs
index 46d45d09661..c2b9253ec35 100644
--- a/clippy_lints/src/casts/ptr_as_ptr.rs
+++ b/clippy_lints/src/casts/ptr_as_ptr.rs
@@ -33,7 +33,7 @@ pub(super) fn check(cx: &LateContext<'_>, expr: &Expr<'_>, msrv: Option<RustcVer
             let turbofish = match &cast_to_hir_ty.kind {
                     TyKind::Infer => Cow::Borrowed(""),
                     TyKind::Ptr(mut_ty) if matches!(mut_ty.ty.kind, TyKind::Infer) => Cow::Borrowed(""),
-                    _ => Cow::Owned(format!("::<{}>", to_pointee_ty)),
+                    _ => Cow::Owned(format!("::<{to_pointee_ty}>")),
                 };
             span_lint_and_sugg(
                 cx,
@@ -41,7 +41,7 @@ pub(super) fn check(cx: &LateContext<'_>, expr: &Expr<'_>, msrv: Option<RustcVer
                 expr.span,
                 "`as` casting between raw pointers without changing its mutability",
                 "try `pointer::cast`, a safer alternative",
-                format!("{}.cast{}()", cast_expr_sugg.maybe_par(), turbofish),
+                format!("{}.cast{turbofish}()", cast_expr_sugg.maybe_par()),
                 applicability,
             );
         }
diff --git a/clippy_lints/src/casts/unnecessary_cast.rs b/clippy_lints/src/casts/unnecessary_cast.rs
index 19d2e6e1d12..21ed7f4844c 100644
--- a/clippy_lints/src/casts/unnecessary_cast.rs
+++ b/clippy_lints/src/casts/unnecessary_cast.rs
@@ -1,4 +1,5 @@
 use clippy_utils::diagnostics::span_lint_and_sugg;
+use clippy_utils::get_parent_expr;
 use clippy_utils::numeric_literal::NumericLiteral;
 use clippy_utils::source::snippet_opt;
 use if_chain::if_chain;
@@ -30,8 +31,10 @@ pub(super) fn check<'tcx>(
         }
     }
 
+    let cast_str = snippet_opt(cx, cast_expr.span).unwrap_or_default();
+
     if let Some(lit) = get_numeric_literal(cast_expr) {
-        let literal_str = snippet_opt(cx, cast_expr.span).unwrap_or_default();
+        let literal_str = &cast_str;
 
         if_chain! {
             if let LitKind::Int(n, _) = lit.node;
@@ -49,12 +52,16 @@ pub(super) fn check<'tcx>(
 
         match lit.node {
             LitKind::Int(_, LitIntType::Unsuffixed) if cast_to.is_integral() => {
-                lint_unnecessary_cast(cx, expr, &literal_str, cast_from, cast_to);
+                lint_unnecessary_cast(cx, expr, literal_str, cast_from, cast_to);
+                return false;
             },
             LitKind::Float(_, LitFloatType::Unsuffixed) if cast_to.is_floating_point() => {
-                lint_unnecessary_cast(cx, expr, &literal_str, cast_from, cast_to);
+                lint_unnecessary_cast(cx, expr, literal_str, cast_from, cast_to);
+                return false;
+            },
+            LitKind::Int(_, LitIntType::Unsuffixed) | LitKind::Float(_, LitFloatType::Unsuffixed) => {
+                return false;
             },
-            LitKind::Int(_, LitIntType::Unsuffixed) | LitKind::Float(_, LitFloatType::Unsuffixed) => {},
             LitKind::Int(_, LitIntType::Signed(_) | LitIntType::Unsigned(_))
             | LitKind::Float(_, LitFloatType::Suffixed(_))
                 if cast_from.kind() == cast_to.kind() =>
@@ -62,48 +69,62 @@ pub(super) fn check<'tcx>(
                 if let Some(src) = snippet_opt(cx, cast_expr.span) {
                     if let Some(num_lit) = NumericLiteral::from_lit_kind(&src, &lit.node) {
                         lint_unnecessary_cast(cx, expr, num_lit.integer, cast_from, cast_to);
+                        return true;
                     }
                 }
             },
-            _ => {
-                if cast_from.kind() == cast_to.kind() && !in_external_macro(cx.sess(), expr.span) {
-                    span_lint_and_sugg(
-                        cx,
-                        UNNECESSARY_CAST,
-                        expr.span,
-                        &format!(
-                            "casting to the same type is unnecessary (`{}` -> `{}`)",
-                            cast_from, cast_to
-                        ),
-                        "try",
-                        literal_str,
-                        Applicability::MachineApplicable,
-                    );
-                    return true;
-                }
-            },
+            _ => {},
         }
     }
 
+    if cast_from.kind() == cast_to.kind() && !in_external_macro(cx.sess(), expr.span) {
+        span_lint_and_sugg(
+            cx,
+            UNNECESSARY_CAST,
+            expr.span,
+            &format!("casting to the same type is unnecessary (`{cast_from}` -> `{cast_to}`)"),
+            "try",
+            cast_str,
+            Applicability::MachineApplicable,
+        );
+        return true;
+    }
+
     false
 }
 
-fn lint_unnecessary_cast(cx: &LateContext<'_>, expr: &Expr<'_>, literal_str: &str, cast_from: Ty<'_>, cast_to: Ty<'_>) {
+fn lint_unnecessary_cast(
+    cx: &LateContext<'_>,
+    expr: &Expr<'_>,
+    raw_literal_str: &str,
+    cast_from: Ty<'_>,
+    cast_to: Ty<'_>,
+) {
     let literal_kind_name = if cast_from.is_integral() { "integer" } else { "float" };
-    let replaced_literal;
-    let matchless = if literal_str.contains(['(', ')']) {
-        replaced_literal = literal_str.replace(['(', ')'], "");
-        &replaced_literal
-    } else {
-        literal_str
+    // first we remove all matches so `-(1)` become `-1`, and remove trailing dots, so `1.` become `1`
+    let literal_str = raw_literal_str
+        .replace(['(', ')'], "")
+        .trim_end_matches('.')
+        .to_string();
+    // we know need to check if the parent is a method call, to add parenthesis accordingly (eg:
+    // (-1).foo() instead of -1.foo())
+    let sugg = if let Some(parent_expr) = get_parent_expr(cx, expr)
+        && let ExprKind::MethodCall(..) = parent_expr.kind
+        && literal_str.starts_with('-')
+        {
+            format!("({literal_str}_{cast_to})")
+
+        } else {
+            format!("{literal_str}_{cast_to}")
     };
+
     span_lint_and_sugg(
         cx,
         UNNECESSARY_CAST,
         expr.span,
-        &format!("casting {} literal to `{}` is unnecessary", literal_kind_name, cast_to),
+        &format!("casting {literal_kind_name} literal to `{cast_to}` is unnecessary"),
         "try",
-        format!("{}_{}", matchless.trim_end_matches('.'), cast_to),
+        sugg,
         Applicability::MachineApplicable,
     );
 }