Simplify some nested if statements

36 files changed, 339 insertions, 379 deletions

diff --git a/compiler/rustc_ast_lowering/src/index.rs b/compiler/rustc_ast_lowering/src/index.rs
index 23729124e21..f90a0612db6 100644
--- a/compiler/rustc_ast_lowering/src/index.rs
+++ b/compiler/rustc_ast_lowering/src/index.rs
@@ -78,26 +78,24 @@ impl<'a, 'hir> NodeCollector<'a, 'hir> {
 
         // Make sure that the DepNode of some node coincides with the HirId
         // owner of that node.
-        if cfg!(debug_assertions) {
-            if hir_id.owner != self.owner {
-                span_bug!(
-                    span,
-                    "inconsistent HirId at `{:?}` for `{:?}`: \
+        if cfg!(debug_assertions) && hir_id.owner != self.owner {
+            span_bug!(
+                span,
+                "inconsistent HirId at `{:?}` for `{:?}`: \
                      current_dep_node_owner={} ({:?}), hir_id.owner={} ({:?})",
-                    self.tcx.sess.source_map().span_to_diagnostic_string(span),
-                    node,
-                    self.tcx
-                        .definitions_untracked()
-                        .def_path(self.owner.def_id)
-                        .to_string_no_crate_verbose(),
-                    self.owner,
-                    self.tcx
-                        .definitions_untracked()
-                        .def_path(hir_id.owner.def_id)
-                        .to_string_no_crate_verbose(),
-                    hir_id.owner,
-                )
-            }
+                self.tcx.sess.source_map().span_to_diagnostic_string(span),
+                node,
+                self.tcx
+                    .definitions_untracked()
+                    .def_path(self.owner.def_id)
+                    .to_string_no_crate_verbose(),
+                self.owner,
+                self.tcx
+                    .definitions_untracked()
+                    .def_path(hir_id.owner.def_id)
+                    .to_string_no_crate_verbose(),
+                hir_id.owner,
+            )
         }
 
         self.nodes[hir_id.local_id] = ParentedNode { parent: self.parent_node, node };
diff --git a/compiler/rustc_ast_passes/src/ast_validation.rs b/compiler/rustc_ast_passes/src/ast_validation.rs
index ed9672a9e79..67dd18fd89c 100644
--- a/compiler/rustc_ast_passes/src/ast_validation.rs
+++ b/compiler/rustc_ast_passes/src/ast_validation.rs
@@ -447,13 +447,13 @@ impl<'a> AstValidator<'a> {
     fn check_item_safety(&self, span: Span, safety: Safety) {
         match self.extern_mod_safety {
             Some(extern_safety) => {
-                if matches!(safety, Safety::Unsafe(_) | Safety::Safe(_)) {
-                    if extern_safety == Safety::Default {
-                        self.dcx().emit_err(errors::InvalidSafetyOnExtern {
-                            item_span: span,
-                            block: Some(self.current_extern_span().shrink_to_lo()),
-                        });
-                    }
+                if matches!(safety, Safety::Unsafe(_) | Safety::Safe(_))
+                    && extern_safety == Safety::Default
+                {
+                    self.dcx().emit_err(errors::InvalidSafetyOnExtern {
+                        item_span: span,
+                        block: Some(self.current_extern_span().shrink_to_lo()),
+                    });
                 }
             }
             None => {
diff --git a/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs b/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs
index a47518fca3f..357ed470748 100644
--- a/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs
+++ b/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs
@@ -2574,33 +2574,31 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, 'infcx, 'tcx> {
         }
         impl<'hir> Visitor<'hir> for ExpressionFinder<'hir> {
             fn visit_expr(&mut self, e: &'hir hir::Expr<'hir>) {
-                if e.span.contains(self.capture_span) {
-                    if let hir::ExprKind::Closure(&hir::Closure {
+                if e.span.contains(self.capture_span)
+                    && let hir::ExprKind::Closure(&hir::Closure {
                         kind: hir::ClosureKind::Closure,
                         body,
                         fn_arg_span,
                         fn_decl: hir::FnDecl { inputs, .. },
                         ..
                     }) = e.kind
-                        && let hir::Node::Expr(body) = self.tcx.hir_node(body.hir_id)
-                    {
-                        self.suggest_arg = "this: &Self".to_string();
-                        if inputs.len() > 0 {
-                            self.suggest_arg.push_str(", ");
-                        }
-                        self.in_closure = true;
-                        self.closure_arg_span = fn_arg_span;
-                        self.visit_expr(body);
-                        self.in_closure = false;
+                    && let hir::Node::Expr(body) = self.tcx.hir_node(body.hir_id)
+                {
+                    self.suggest_arg = "this: &Self".to_string();
+                    if inputs.len() > 0 {
+                        self.suggest_arg.push_str(", ");
                     }
+                    self.in_closure = true;
+                    self.closure_arg_span = fn_arg_span;
+                    self.visit_expr(body);
+                    self.in_closure = false;
                 }
-                if let hir::Expr { kind: hir::ExprKind::Path(path), .. } = e {
-                    if let hir::QPath::Resolved(_, hir::Path { segments: [seg], .. }) = path
-                        && seg.ident.name == kw::SelfLower
-                        && self.in_closure
-                    {
-                        self.closure_change_spans.push(e.span);
-                    }
+                if let hir::Expr { kind: hir::ExprKind::Path(path), .. } = e
+                    && let hir::QPath::Resolved(_, hir::Path { segments: [seg], .. }) = path
+                    && seg.ident.name == kw::SelfLower
+                    && self.in_closure
+                {
+                    self.closure_change_spans.push(e.span);
                 }
                 hir::intravisit::walk_expr(self, e);
             }
@@ -2609,8 +2607,7 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, 'infcx, 'tcx> {
                 if let hir::Pat { kind: hir::PatKind::Binding(_, hir_id, _ident, _), .. } =
                     local.pat
                     && let Some(init) = local.init
-                {
-                    if let hir::Expr {
+                    && let hir::Expr {
                         kind:
                             hir::ExprKind::Closure(&hir::Closure {
                                 kind: hir::ClosureKind::Closure,
@@ -2618,11 +2615,11 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, 'infcx, 'tcx> {
                             }),
                         ..
                     } = init
-                        && init.span.contains(self.capture_span)
-                    {
-                        self.closure_local_id = Some(*hir_id);
-                    }
+                    && init.span.contains(self.capture_span)
+                {
+                    self.closure_local_id = Some(*hir_id);
                 }
+
                 hir::intravisit::walk_local(self, local);
             }
 
diff --git a/compiler/rustc_borrowck/src/lib.rs b/compiler/rustc_borrowck/src/lib.rs
index d5f297a5913..d98c66b0f3b 100644
--- a/compiler/rustc_borrowck/src/lib.rs
+++ b/compiler/rustc_borrowck/src/lib.rs
@@ -2069,12 +2069,12 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, '_, 'tcx> {
                 // no move out from an earlier location) then this is an attempt at initialization
                 // of the union - we should error in that case.
                 let tcx = this.infcx.tcx;
-                if base.ty(this.body(), tcx).ty.is_union() {
-                    if this.move_data.path_map[mpi].iter().any(|moi| {
+                if base.ty(this.body(), tcx).ty.is_union()
+                    && this.move_data.path_map[mpi].iter().any(|moi| {
                         this.move_data.moves[*moi].source.is_predecessor_of(location, this.body)
-                    }) {
-                        return;
-                    }
+                    })
+                {
+                    return;
                 }
 
                 this.report_use_of_moved_or_uninitialized(
diff --git a/compiler/rustc_borrowck/src/type_check/liveness/trace.rs b/compiler/rustc_borrowck/src/type_check/liveness/trace.rs
index 4d47863ae76..1ac27573453 100644
--- a/compiler/rustc_borrowck/src/type_check/liveness/trace.rs
+++ b/compiler/rustc_borrowck/src/type_check/liveness/trace.rs
@@ -353,11 +353,11 @@ impl<'a, 'typeck, 'b, 'tcx> LivenessResults<'a, 'typeck, 'b, 'tcx> {
             let location = self.cx.elements.to_location(drop_point);
             debug_assert_eq!(self.cx.body.terminator_loc(location.block), location,);
 
-            if self.cx.initialized_at_terminator(location.block, mpi) {
-                if self.drop_live_at.insert(drop_point) {
-                    self.drop_locations.push(location);
-                    self.stack.push(drop_point);
-                }
+            if self.cx.initialized_at_terminator(location.block, mpi)
+                && self.drop_live_at.insert(drop_point)
+            {
+                self.drop_locations.push(location);
+                self.stack.push(drop_point);
             }
         }
 
diff --git a/compiler/rustc_codegen_llvm/src/back/lto.rs b/compiler/rustc_codegen_llvm/src/back/lto.rs
index 09896b89ebf..2ebe0be53aa 100644
--- a/compiler/rustc_codegen_llvm/src/back/lto.rs
+++ b/compiler/rustc_codegen_llvm/src/back/lto.rs
@@ -92,11 +92,9 @@ fn prepare_lto(
                     dcx.emit_err(LtoDylib);
                     return Err(FatalError);
                 }
-            } else if *crate_type == CrateType::ProcMacro {
-                if !cgcx.opts.unstable_opts.dylib_lto {
-                    dcx.emit_err(LtoProcMacro);
-                    return Err(FatalError);
-                }
+            } else if *crate_type == CrateType::ProcMacro && !cgcx.opts.unstable_opts.dylib_lto {
+                dcx.emit_err(LtoProcMacro);
+                return Err(FatalError);
             }
         }
 
diff --git a/compiler/rustc_codegen_ssa/src/codegen_attrs.rs b/compiler/rustc_codegen_ssa/src/codegen_attrs.rs
index 4ab20c154cc..9149c602296 100644
--- a/compiler/rustc_codegen_ssa/src/codegen_attrs.rs
+++ b/compiler/rustc_codegen_ssa/src/codegen_attrs.rs
@@ -617,32 +617,29 @@ fn codegen_fn_attrs(tcx: TyCtxt<'_>, did: LocalDefId) -> CodegenFnAttrs {
     // purpose functions as they wouldn't have the right target features
     // enabled. For that reason we also forbid #[inline(always)] as it can't be
     // respected.
-    if !codegen_fn_attrs.target_features.is_empty() {
-        if codegen_fn_attrs.inline == InlineAttr::Always {
-            if let Some(span) = inline_span {
-                tcx.dcx().span_err(
-                    span,
-                    "cannot use `#[inline(always)]` with \
+    if !codegen_fn_attrs.target_features.is_empty() && codegen_fn_attrs.inline == InlineAttr::Always
+    {
+        if let Some(span) = inline_span {
+            tcx.dcx().span_err(
+                span,
+                "cannot use `#[inline(always)]` with \
                      `#[target_feature]`",
-                );
-            }
+            );
         }
     }
 
-    if !codegen_fn_attrs.no_sanitize.is_empty() {
-        if codegen_fn_attrs.inline == InlineAttr::Always {
-            if let (Some(no_sanitize_span), Some(inline_span)) = (no_sanitize_span, inline_span) {
-                let hir_id = tcx.local_def_id_to_hir_id(did);
-                tcx.node_span_lint(
-                    lint::builtin::INLINE_NO_SANITIZE,
-                    hir_id,
-                    no_sanitize_span,
-                    |lint| {
-                        lint.primary_message("`no_sanitize` will have no effect after inlining");
-                        lint.span_note(inline_span, "inlining requested here");
-                    },
-                )
-            }
+    if !codegen_fn_attrs.no_sanitize.is_empty() && codegen_fn_attrs.inline == InlineAttr::Always {
+        if let (Some(no_sanitize_span), Some(inline_span)) = (no_sanitize_span, inline_span) {
+            let hir_id = tcx.local_def_id_to_hir_id(did);
+            tcx.node_span_lint(
+                lint::builtin::INLINE_NO_SANITIZE,
+                hir_id,
+                no_sanitize_span,
+                |lint| {
+                    lint.primary_message("`no_sanitize` will have no effect after inlining");
+                    lint.span_note(inline_span, "inlining requested here");
+                },
+            )
         }
     }
 
diff --git a/compiler/rustc_const_eval/src/interpret/eval_context.rs b/compiler/rustc_const_eval/src/interpret/eval_context.rs
index dd744c51f23..16d40fcceb6 100644
--- a/compiler/rustc_const_eval/src/interpret/eval_context.rs
+++ b/compiler/rustc_const_eval/src/interpret/eval_context.rs
@@ -16,7 +16,7 @@ use rustc_span::Span;
 use rustc_target::abi::call::FnAbi;
 use rustc_target::abi::{Align, HasDataLayout, Size, TargetDataLayout};
 use rustc_trait_selection::traits::ObligationCtxt;
-use tracing::{debug, trace};
+use tracing::{debug, instrument, trace};
 
 use super::{
     err_inval, throw_inval, throw_ub, throw_ub_custom, Frame, FrameInfo, GlobalId, InterpErrorInfo,
@@ -315,6 +315,7 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
 
     /// Check if the two things are equal in the current param_env, using an infctx to get proper
     /// equality checks.
+    #[instrument(level = "trace", skip(self), ret)]
     pub(super) fn eq_in_param_env<T>(&self, a: T, b: T) -> bool
     where
         T: PartialEq + TypeFoldable<TyCtxt<'tcx>> + ToTrace<'tcx>,
@@ -330,13 +331,20 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
         // equate the two trait refs after normalization
         let a = ocx.normalize(&cause, self.param_env, a);
         let b = ocx.normalize(&cause, self.param_env, b);
-        if ocx.eq(&cause, self.param_env, a, b).is_ok() {
-            if ocx.select_all_or_error().is_empty() {
-                // All good.
-                return true;
-            }
+
+        if let Err(terr) = ocx.eq(&cause, self.param_env, a, b) {
+            trace!(?terr);
+            return false;
+        }
+
+        let errors = ocx.select_all_or_error();
+        if !errors.is_empty() {
+            trace!(?errors);
+            return false;
         }
-        return false;
+
+        // All good.
+        true
     }
 
     /// Walks up the callstack from the intrinsic's callsite, searching for the first callsite in a
diff --git a/compiler/rustc_driver_impl/src/pretty.rs b/compiler/rustc_driver_impl/src/pretty.rs
index c973fcec0e1..74225d646bd 100644
--- a/compiler/rustc_driver_impl/src/pretty.rs
+++ b/compiler/rustc_driver_impl/src/pretty.rs
@@ -222,10 +222,8 @@ impl<'tcx> PrintExtra<'tcx> {
 }
 
 pub fn print<'tcx>(sess: &Session, ppm: PpMode, ex: PrintExtra<'tcx>) {
-    if ppm.needs_analysis() {
-        if ex.tcx().analysis(()).is_err() {
-            FatalError.raise();
-        }
+    if ppm.needs_analysis() && ex.tcx().analysis(()).is_err() {
+        FatalError.raise();
     }
 
     let (src, src_name) = get_source(sess);
diff --git a/compiler/rustc_hir_analysis/src/check/mod.rs b/compiler/rustc_hir_analysis/src/check/mod.rs
index 6820a44f141..dbdad2eb41d 100644
--- a/compiler/rustc_hir_analysis/src/check/mod.rs
+++ b/compiler/rustc_hir_analysis/src/check/mod.rs
@@ -186,17 +186,15 @@ fn maybe_check_static_with_link_section(tcx: TyCtxt<'_>, id: LocalDefId) {
 
     if let Ok(alloc) = tcx.eval_static_initializer(id.to_def_id())
         && alloc.inner().provenance().ptrs().len() != 0
-    {
-        if attrs
+        && attrs
             .link_section
             .map(|link_section| !link_section.as_str().starts_with(".init_array"))
             .unwrap()
-        {
-            let msg = "statics with a custom `#[link_section]` must be a \
+    {
+        let msg = "statics with a custom `#[link_section]` must be a \
                         simple list of bytes on the wasm target with no \
                         extra levels of indirection such as references";
-            tcx.dcx().span_err(tcx.def_span(id), msg);
-        }
+        tcx.dcx().span_err(tcx.def_span(id), msg);
     }
 }
 
diff --git a/compiler/rustc_hir_analysis/src/coherence/mod.rs b/compiler/rustc_hir_analysis/src/coherence/mod.rs
index db809e4837d..f2a97d06771 100644
--- a/compiler/rustc_hir_analysis/src/coherence/mod.rs
+++ b/compiler/rustc_hir_analysis/src/coherence/mod.rs
@@ -53,17 +53,15 @@ fn enforce_trait_manually_implementable(
 ) -> Result<(), ErrorGuaranteed> {
     let impl_header_span = tcx.def_span(impl_def_id);
 
-    if tcx.is_lang_item(trait_def_id, LangItem::Freeze) {
-        if !tcx.features().freeze_impls {
-            feature_err(
-                &tcx.sess,
-                sym::freeze_impls,
-                impl_header_span,
-                "explicit impls for the `Freeze` trait are not permitted",
-            )
-            .with_span_label(impl_header_span, format!("impl of `Freeze` not allowed"))
-            .emit();
-        }
+    if tcx.is_lang_item(trait_def_id, LangItem::Freeze) && !tcx.features().freeze_impls {
+        feature_err(
+            &tcx.sess,
+            sym::freeze_impls,
+            impl_header_span,
+            "explicit impls for the `Freeze` trait are not permitted",
+        )
+        .with_span_label(impl_header_span, format!("impl of `Freeze` not allowed"))
+        .emit();
     }
 
     // Disallow *all* explicit impls of traits marked `#[rustc_deny_explicit_impl]`
diff --git a/compiler/rustc_hir_analysis/src/errors/wrong_number_of_generic_args.rs b/compiler/rustc_hir_analysis/src/errors/wrong_number_of_generic_args.rs
index da89f5769d1..97402dd1109 100644
--- a/compiler/rustc_hir_analysis/src/errors/wrong_number_of_generic_args.rs
+++ b/compiler/rustc_hir_analysis/src/errors/wrong_number_of_generic_args.rs
@@ -827,20 +827,18 @@ impl<'a, 'tcx> WrongNumberOfGenericArgs<'a, 'tcx> {
 
             if num_generic_args_supplied_to_trait + num_assoc_fn_excess_args
                 == num_trait_generics_except_self
+                && let Some(span) = self.gen_args.span_ext()
+                && let Ok(snippet) = self.tcx.sess.source_map().span_to_snippet(span)
             {
-                if let Some(span) = self.gen_args.span_ext()
-                    && let Ok(snippet) = self.tcx.sess.source_map().span_to_snippet(span)
-                {
-                    let sugg = vec![
-                        (
-                            self.path_segment.ident.span,
-                            format!("{}::{}", snippet, self.path_segment.ident),
-                        ),
-                        (span.with_lo(self.path_segment.ident.span.hi()), "".to_owned()),
-                    ];
+                let sugg = vec![
+                    (
+                        self.path_segment.ident.span,
+                        format!("{}::{}", snippet, self.path_segment.ident),
+                    ),
+                    (span.with_lo(self.path_segment.ident.span.hi()), "".to_owned()),
+                ];
 
-                    err.multipart_suggestion(msg, sugg, Applicability::MaybeIncorrect);
-                }
+                err.multipart_suggestion(msg, sugg, Applicability::MaybeIncorrect);
             }
         }
     }
diff --git a/compiler/rustc_hir_typeck/src/cast.rs b/compiler/rustc_hir_typeck/src/cast.rs
index 1e1e007862e..36892aaf80c 100644
--- a/compiler/rustc_hir_typeck/src/cast.rs
+++ b/compiler/rustc_hir_typeck/src/cast.rs
@@ -732,12 +732,11 @@ impl<'a, 'tcx> CastCheck<'tcx> {
             }
             _ => return Err(CastError::NonScalar),
         };
-        if let ty::Adt(adt_def, _) = *self.expr_ty.kind() {
-            if adt_def.did().krate != LOCAL_CRATE {
-                if adt_def.variants().iter().any(VariantDef::is_field_list_non_exhaustive) {
-                    return Err(CastError::ForeignNonExhaustiveAdt);
-                }
-            }
+        if let ty::Adt(adt_def, _) = *self.expr_ty.kind()
+            && adt_def.did().krate != LOCAL_CRATE
+            && adt_def.variants().iter().any(VariantDef::is_field_list_non_exhaustive)
+        {
+            return Err(CastError::ForeignNonExhaustiveAdt);
         }
         match (t_from, t_cast) {
             // These types have invariants! can't cast into them.
diff --git a/compiler/rustc_hir_typeck/src/expr.rs b/compiler/rustc_hir_typeck/src/expr.rs
index 9bad5633b69..197f802960f 100644
--- a/compiler/rustc_hir_typeck/src/expr.rs
+++ b/compiler/rustc_hir_typeck/src/expr.rs
@@ -1780,16 +1780,14 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         }
 
         // Make sure the programmer specified correct number of fields.
-        if adt_kind == AdtKind::Union {
-            if hir_fields.len() != 1 {
-                struct_span_code_err!(
-                    self.dcx(),
-                    span,
-                    E0784,
-                    "union expressions should have exactly one field",
-                )
-                .emit();
-            }
+        if adt_kind == AdtKind::Union && hir_fields.len() != 1 {
+            struct_span_code_err!(
+                self.dcx(),
+                span,
+                E0784,
+                "union expressions should have exactly one field",
+            )
+            .emit();
         }
 
         // If check_expr_struct_fields hit an error, do not attempt to populate
diff --git a/compiler/rustc_hir_typeck/src/method/suggest.rs b/compiler/rustc_hir_typeck/src/method/suggest.rs
index 14ad5830111..6ec4a005bed 100644
--- a/compiler/rustc_hir_typeck/src/method/suggest.rs
+++ b/compiler/rustc_hir_typeck/src/method/suggest.rs
@@ -1252,11 +1252,11 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                             && suggested_bounds.contains(parent)
                         {
                             // We don't suggest `PartialEq` when we already suggest `Eq`.
-                        } else if !suggested_bounds.contains(pred) {
-                            if collect_type_param_suggestions(self_ty, *pred, &p) {
-                                suggested = true;
-                                suggested_bounds.insert(pred);
-                            }
+                        } else if !suggested_bounds.contains(pred)
+                            && collect_type_param_suggestions(self_ty, *pred, &p)
+                        {
+                            suggested = true;
+                            suggested_bounds.insert(pred);
                         }
                         (
                             match parent_pred {
@@ -1267,14 +1267,13 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                                         if !suggested
                                             && !suggested_bounds.contains(pred)
                                             && !suggested_bounds.contains(parent_pred)
-                                        {
-                                            if collect_type_param_suggestions(
+                                            && collect_type_param_suggestions(
                                                 self_ty,
                                                 *parent_pred,
                                                 &p,
-                                            ) {
-                                                suggested_bounds.insert(pred);
-                                            }
+                                            )
+                                        {
+                                            suggested_bounds.insert(pred);
                                         }
                                         format!("`{p}`\nwhich is required by `{parent_p}`")
                                     }
diff --git a/compiler/rustc_lint/src/builtin.rs b/compiler/rustc_lint/src/builtin.rs
index 7de92a43a9a..8b92180e9bd 100644
--- a/compiler/rustc_lint/src/builtin.rs
+++ b/compiler/rustc_lint/src/builtin.rs
@@ -429,10 +429,8 @@ impl MissingDoc {
         // Only check publicly-visible items, using the result from the privacy pass.
         // It's an option so the crate root can also use this function (it doesn't
         // have a `NodeId`).
-        if def_id != CRATE_DEF_ID {
-            if !cx.effective_visibilities.is_exported(def_id) {
-                return;
-            }
+        if def_id != CRATE_DEF_ID && !cx.effective_visibilities.is_exported(def_id) {
+            return;
         }
 
         let attrs = cx.tcx.hir().attrs(cx.tcx.local_def_id_to_hir_id(def_id));
diff --git a/compiler/rustc_middle/src/middle/stability.rs b/compiler/rustc_middle/src/middle/stability.rs
index 3b8861378e0..86dca27f04f 100644
--- a/compiler/rustc_middle/src/middle/stability.rs
+++ b/compiler/rustc_middle/src/middle/stability.rs
@@ -444,10 +444,11 @@ impl<'tcx> TyCtxt<'tcx> {
                 // the `-Z force-unstable-if-unmarked` flag present (we're
                 // compiling a compiler crate), then let this missing feature
                 // annotation slide.
-                if feature == sym::rustc_private && issue == NonZero::new(27812) {
-                    if self.sess.opts.unstable_opts.force_unstable_if_unmarked {
-                        return EvalResult::Allow;
-                    }
+                if feature == sym::rustc_private
+                    && issue == NonZero::new(27812)
+                    && self.sess.opts.unstable_opts.force_unstable_if_unmarked
+                {
+                    return EvalResult::Allow;
                 }
 
                 if matches!(allow_unstable, AllowUnstable::Yes) {
diff --git a/compiler/rustc_middle/src/mir/interpret/allocation.rs b/compiler/rustc_middle/src/mir/interpret/allocation.rs
index cd56d0edc05..f5fef249167 100644
--- a/compiler/rustc_middle/src/mir/interpret/allocation.rs
+++ b/compiler/rustc_middle/src/mir/interpret/allocation.rs
@@ -448,22 +448,20 @@ impl<Prov: Provenance, Extra, Bytes: AllocBytes> Allocation<Prov, Extra, Bytes>
                 bad: uninit_range,
             }))
         })?;
-        if !Prov::OFFSET_IS_ADDR {
-            if !self.provenance.range_empty(range, cx) {
-                // Find the provenance.
-                let (offset, _prov) = self
-                    .provenance
-                    .range_get_ptrs(range, cx)
-                    .first()
-                    .copied()
-                    .expect("there must be provenance somewhere here");
-                let start = offset.max(range.start); // the pointer might begin before `range`!
-                let end = (offset + cx.pointer_size()).min(range.end()); // the pointer might end after `range`!
-                return Err(AllocError::ReadPointerAsInt(Some(BadBytesAccess {
-                    access: range,
-                    bad: AllocRange::from(start..end),
-                })));
-            }
+        if !Prov::OFFSET_IS_ADDR && !self.provenance.range_empty(range, cx) {
+            // Find the provenance.
+            let (offset, _prov) = self
+                .provenance
+                .range_get_ptrs(range, cx)
+                .first()
+                .copied()
+                .expect("there must be provenance somewhere here");
+            let start = offset.max(range.start); // the pointer might begin before `range`!
+            let end = (offset + cx.pointer_size()).min(range.end()); // the pointer might end after `range`!
+            return Err(AllocError::ReadPointerAsInt(Some(BadBytesAccess {
+                access: range,
+                bad: AllocRange::from(start..end),
+            })));
         }
         Ok(self.get_bytes_unchecked(range))
     }
diff --git a/compiler/rustc_middle/src/ty/context.rs b/compiler/rustc_middle/src/ty/context.rs
index 56fcfe8e798..75d5c8d1711 100644
--- a/compiler/rustc_middle/src/ty/context.rs
+++ b/compiler/rustc_middle/src/ty/context.rs
@@ -2606,33 +2606,31 @@ impl<'tcx> TyCtxt<'tcx> {
     /// With `cfg(debug_assertions)`, assert that args are compatible with their generics,
     /// and print out the args if not.
     pub fn debug_assert_args_compatible(self, def_id: DefId, args: &'tcx [ty::GenericArg<'tcx>]) {
-        if cfg!(debug_assertions) {
-            if !self.check_args_compatible(def_id, args) {
-                if let DefKind::AssocTy = self.def_kind(def_id)
-                    && let DefKind::Impl { of_trait: false } = self.def_kind(self.parent(def_id))
-                {
-                    bug!(
-                        "args not compatible with generics for {}: args={:#?}, generics={:#?}",
-                        self.def_path_str(def_id),
-                        args,
-                        // Make `[Self, GAT_ARGS...]` (this could be simplified)
-                        self.mk_args_from_iter(
-                            [self.types.self_param.into()].into_iter().chain(
-                                self.generics_of(def_id)
-                                    .own_args(ty::GenericArgs::identity_for_item(self, def_id))
-                                    .iter()
-                                    .copied()
-                            )
+        if cfg!(debug_assertions) && !self.check_args_compatible(def_id, args) {
+            if let DefKind::AssocTy = self.def_kind(def_id)
+                && let DefKind::Impl { of_trait: false } = self.def_kind(self.parent(def_id))
+            {
+                bug!(
+                    "args not compatible with generics for {}: args={:#?}, generics={:#?}",
+                    self.def_path_str(def_id),
+                    args,
+                    // Make `[Self, GAT_ARGS...]` (this could be simplified)
+                    self.mk_args_from_iter(
+                        [self.types.self_param.into()].into_iter().chain(
+                            self.generics_of(def_id)
+                                .own_args(ty::GenericArgs::identity_for_item(self, def_id))
+                                .iter()
+                                .copied()
                         )
-                    );
-                } else {
-                    bug!(
-                        "args not compatible with generics for {}: args={:#?}, generics={:#?}",
-                        self.def_path_str(def_id),
-                        args,
-                        ty::GenericArgs::identity_for_item(self, def_id)
-                    );
-                }
+                    )
+                );
+            } else {
+                bug!(
+                    "args not compatible with generics for {}: args={:#?}, generics={:#?}",
+                    self.def_path_str(def_id),
+                    args,
+                    ty::GenericArgs::identity_for_item(self, def_id)
+                );
             }
         }
     }
diff --git a/compiler/rustc_middle/src/ty/layout.rs b/compiler/rustc_middle/src/ty/layout.rs
index 8cec8eac189..254a0119920 100644
--- a/compiler/rustc_middle/src/ty/layout.rs
+++ b/compiler/rustc_middle/src/ty/layout.rs
@@ -1183,10 +1183,10 @@ pub fn fn_can_unwind(tcx: TyCtxt<'_>, fn_def_id: Option<DefId>, abi: SpecAbi) ->
         //
         // This is not part of `codegen_fn_attrs` as it can differ between crates
         // and therefore cannot be computed in core.
-        if tcx.sess.opts.unstable_opts.panic_in_drop == PanicStrategy::Abort {
-            if tcx.is_lang_item(did, LangItem::DropInPlace) {
-                return false;
-            }
+        if tcx.sess.opts.unstable_opts.panic_in_drop == PanicStrategy::Abort
+            && tcx.is_lang_item(did, LangItem::DropInPlace)
+        {
+            return false;
         }
     }
 
diff --git a/compiler/rustc_middle/src/ty/print/pretty.rs b/compiler/rustc_middle/src/ty/print/pretty.rs
index f1ff90831b0..7f783f75f3a 100644
--- a/compiler/rustc_middle/src/ty/print/pretty.rs
+++ b/compiler/rustc_middle/src/ty/print/pretty.rs
@@ -3361,10 +3361,8 @@ pub fn trimmed_def_paths(tcx: TyCtxt<'_>, (): ()) -> DefIdMap<Symbol> {
                     // name.
                     //
                     // Any stable ordering would be fine here though.
-                    if *v.get() != symbol {
-                        if v.get().as_str() > symbol.as_str() {
-                            v.insert(symbol);
-                        }
+                    if *v.get() != symbol && v.get().as_str() > symbol.as_str() {
+                        v.insert(symbol);
                     }
                 }
                 Vacant(v) => {
diff --git a/compiler/rustc_mir_build/src/build/coverageinfo/mcdc.rs b/compiler/rustc_mir_build/src/build/coverageinfo/mcdc.rs
index 3aa6e708476..6019a93e787 100644
--- a/compiler/rustc_mir_build/src/build/coverageinfo/mcdc.rs
+++ b/compiler/rustc_mir_build/src/build/coverageinfo/mcdc.rs
@@ -268,10 +268,9 @@ impl Builder<'_, '_> {
     pub(crate) fn mcdc_decrement_depth_if_enabled(&mut self) {
         if let Some(coverage_info) = self.coverage_info.as_mut()
             && let Some(mcdc_info) = coverage_info.mcdc_info.as_mut()
+            && mcdc_info.state.decision_ctx_stack.pop().is_none()
         {
-            if mcdc_info.state.decision_ctx_stack.pop().is_none() {
-                bug!("Unexpected empty decision stack");
-            }
+            bug!("Unexpected empty decision stack");
         };
     }
 }
diff --git a/compiler/rustc_mir_transform/src/check_const_item_mutation.rs b/compiler/rustc_mir_transform/src/check_const_item_mutation.rs
index 048dd9ccb8f..9c3cbbe1fc9 100644
--- a/compiler/rustc_mir_transform/src/check_const_item_mutation.rs
+++ b/compiler/rustc_mir_transform/src/check_const_item_mutation.rs
@@ -95,19 +95,19 @@ impl<'tcx> Visitor<'tcx> for ConstMutationChecker<'_, 'tcx> {
             // Check for assignment to fields of a constant
             // Assigning directly to a constant (e.g. `FOO = true;`) is a hard error,
             // so emitting a lint would be redundant.
-            if !lhs.projection.is_empty() {
-                if let Some(def_id) = self.is_const_item_without_destructor(lhs.local)
-                    && let Some((lint_root, span, item)) =
-                        self.should_lint_const_item_usage(lhs, def_id, loc)
-                {
-                    self.tcx.emit_node_span_lint(
-                        CONST_ITEM_MUTATION,
-                        lint_root,
-                        span,
-                        errors::ConstMutate::Modify { konst: item },
-                    );
-                }
+            if !lhs.projection.is_empty()
+                && let Some(def_id) = self.is_const_item_without_destructor(lhs.local)
+                && let Some((lint_root, span, item)) =
+                    self.should_lint_const_item_usage(lhs, def_id, loc)
+            {
+                self.tcx.emit_node_span_lint(
+                    CONST_ITEM_MUTATION,
+                    lint_root,
+                    span,
+                    errors::ConstMutate::Modify { konst: item },
+                );
             }
+
             // We are looking for MIR of the form:
             //
             // ```
diff --git a/compiler/rustc_mir_transform/src/deduce_param_attrs.rs b/compiler/rustc_mir_transform/src/deduce_param_attrs.rs
index c645bbee08a..c0cb0e641ac 100644
--- a/compiler/rustc_mir_transform/src/deduce_param_attrs.rs
+++ b/compiler/rustc_mir_transform/src/deduce_param_attrs.rs
@@ -168,17 +168,16 @@ pub(super) fn deduced_param_attrs<'tcx>(
     // Codegen won't use this information for anything if all the function parameters are passed
     // directly. Detect that and bail, for compilation speed.
     let fn_ty = tcx.type_of(def_id).instantiate_identity();
-    if matches!(fn_ty.kind(), ty::FnDef(..)) {
-        if fn_ty
+    if matches!(fn_ty.kind(), ty::FnDef(..))
+        && fn_ty
             .fn_sig(tcx)
             .inputs()
             .skip_binder()
             .iter()
             .cloned()
             .all(type_will_always_be_passed_directly)
-        {
-            return &[];
-        }
+    {
+        return &[];
     }
 
     // Don't deduce any attributes for functions that have no MIR.
diff --git a/compiler/rustc_mir_transform/src/known_panics_lint.rs b/compiler/rustc_mir_transform/src/known_panics_lint.rs
index 46b17c3c7e0..f123f39bf42 100644
--- a/compiler/rustc_mir_transform/src/known_panics_lint.rs
+++ b/compiler/rustc_mir_transform/src/known_panics_lint.rs
@@ -378,19 +378,19 @@ impl<'mir, 'tcx> ConstPropagator<'mir, 'tcx> {
         if let (Some(l), Some(r)) = (l, r)
             && l.layout.ty.is_integral()
             && op.is_overflowing()
-        {
-            if self.use_ecx(|this| {
+            && self.use_ecx(|this| {
                 let (_res, overflow) = this.ecx.binary_op(op, &l, &r)?.to_scalar_pair();
                 overflow.to_bool()
-            })? {
-                self.report_assert_as_lint(
-                    location,
-                    AssertLintKind::ArithmeticOverflow,
-                    AssertKind::Overflow(op, l.to_const_int(), r.to_const_int()),
-                );
-                return None;
-            }
+            })?
+        {
+            self.report_assert_as_lint(
+                location,
+                AssertLintKind::ArithmeticOverflow,
+                AssertKind::Overflow(op, l.to_const_int(), r.to_const_int()),
+            );
+            return None;
         }
+
         Some(())
     }
 
diff --git a/compiler/rustc_monomorphize/src/partitioning.rs b/compiler/rustc_monomorphize/src/partitioning.rs
index 0d295b8f280..2d9dbdbaec2 100644
--- a/compiler/rustc_monomorphize/src/partitioning.rs
+++ b/compiler/rustc_monomorphize/src/partitioning.rs
@@ -504,10 +504,8 @@ fn compute_inlined_overlap<'tcx>(cgu1: &CodegenUnit<'tcx>, cgu2: &CodegenUnit<'t
 
     let mut overlap = 0;
     for (item, data) in src_cgu.items().iter() {
-        if data.inlined {
-            if dst_cgu.items().contains_key(item) {
-                overlap += data.size_estimate;
-            }
+        if data.inlined && dst_cgu.items().contains_key(item) {
+            overlap += data.size_estimate;
         }
     }
     overlap
diff --git a/compiler/rustc_next_trait_solver/src/canonicalizer.rs b/compiler/rustc_next_trait_solver/src/canonicalizer.rs
index 394518daa42..196ddeb2443 100644
--- a/compiler/rustc_next_trait_solver/src/canonicalizer.rs
+++ b/compiler/rustc_next_trait_solver/src/canonicalizer.rs
@@ -185,10 +185,8 @@ impl<'a, D: SolverDelegate<Interner = I>, I: Interner> Canonicalizer<'a, D, I> {
                 for var in var_infos.iter_mut() {
                     // We simply put all regions from the input into the highest
                     // compressed universe, so we only deal with them at the end.
-                    if !var.is_region() {
-                        if is_existential == var.is_existential() {
-                            update_uv(var, orig_uv, is_existential)
-                        }
+                    if !var.is_region() && is_existential == var.is_existential() {
+                        update_uv(var, orig_uv, is_existential)
                     }
                 }
             }
diff --git a/compiler/rustc_parse/src/parser/path.rs b/compiler/rustc_parse/src/parser/path.rs
index 8ee40ecd77e..42039c621d6 100644
--- a/compiler/rustc_parse/src/parser/path.rs
+++ b/compiler/rustc_parse/src/parser/path.rs
@@ -671,12 +671,12 @@ impl<'a> Parser<'a> {
                     err.emit();
                     continue;
                 }
-                if !self.token.kind.should_end_const_arg() {
-                    if self.handle_ambiguous_unbraced_const_arg(&mut args)? {
-                        // We've managed to (partially) recover, so continue trying to parse
-                        // arguments.
-                        continue;
-                    }
+                if !self.token.kind.should_end_const_arg()
+                    && self.handle_ambiguous_unbraced_const_arg(&mut args)?
+                {
+                    // We've managed to (partially) recover, so continue trying to parse
+                    // arguments.
+                    continue;
                 }
                 break;
             }
diff --git a/compiler/rustc_passes/src/stability.rs b/compiler/rustc_passes/src/stability.rs
index ba4c300ea61..e2c9067c0b9 100644
--- a/compiler/rustc_passes/src/stability.rs
+++ b/compiler/rustc_passes/src/stability.rs
@@ -174,16 +174,14 @@ impl<'a, 'tcx> Annotator<'a, 'tcx> {
 
         // If the current node is a function, has const stability attributes and if it doesn not have an intrinsic ABI,
         // check if the function/method is const or the parent impl block is const
-        if let (Some(const_span), Some(fn_sig)) = (const_span, fn_sig) {
-            if fn_sig.header.abi != Abi::RustIntrinsic && !fn_sig.header.is_const() {
-                if !self.in_trait_impl
-                    || (self.in_trait_impl && !self.tcx.is_const_fn_raw(def_id.to_def_id()))
-                {
-                    self.tcx
-                        .dcx()
-                        .emit_err(errors::MissingConstErr { fn_sig_span: fn_sig.span, const_span });
-                }
-            }
+        if let (Some(const_span), Some(fn_sig)) = (const_span, fn_sig)
+            && fn_sig.header.abi != Abi::RustIntrinsic
+            && !fn_sig.header.is_const()
+            && (!self.in_trait_impl || !self.tcx.is_const_fn_raw(def_id.to_def_id()))
+        {
+            self.tcx
+                .dcx()
+                .emit_err(errors::MissingConstErr { fn_sig_span: fn_sig.span, const_span });
         }
 
         // `impl const Trait for Type` items forward their const stability to their
diff --git a/compiler/rustc_resolve/src/diagnostics.rs b/compiler/rustc_resolve/src/diagnostics.rs
index bcbdf627b56..b32eb5854ca 100644
--- a/compiler/rustc_resolve/src/diagnostics.rs
+++ b/compiler/rustc_resolve/src/diagnostics.rs
@@ -1233,64 +1233,63 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
                     && ns == namespace
                     && in_module != parent_scope.module
                     && !ident.span.normalize_to_macros_2_0().from_expansion()
+                    && filter_fn(res)
                 {
-                    if filter_fn(res) {
-                        // create the path
-                        let mut segms = if lookup_ident.span.at_least_rust_2018() {
-                            // crate-local absolute paths start with `crate::` in edition 2018
-                            // FIXME: may also be stabilized for Rust 2015 (Issues #45477, #44660)
-                            crate_path.clone()
-                        } else {
-                            ThinVec::new()
-                        };
-                        segms.append(&mut path_segments.clone());
+                    // create the path
+                    let mut segms = if lookup_ident.span.at_least_rust_2018() {
+                        // crate-local absolute paths start with `crate::` in edition 2018
+                        // FIXME: may also be stabilized for Rust 2015 (Issues #45477, #44660)
+                        crate_path.clone()
+                    } else {
+                        ThinVec::new()
+                    };
+                    segms.append(&mut path_segments.clone());
 
-                        segms.push(ast::PathSegment::from_ident(ident));
-                        let path = Path { span: name_binding.span, segments: segms, tokens: None };
+                    segms.push(ast::PathSegment::from_ident(ident));
+                    let path = Path { span: name_binding.span, segments: segms, tokens: None };
 
-                        if child_accessible {
-                            // Remove invisible match if exists
-                            if let Some(idx) = candidates
-                                .iter()
-                                .position(|v: &ImportSuggestion| v.did == did && !v.accessible)
-                            {
-                                candidates.remove(idx);
-                            }
+                    if child_accessible {
+                        // Remove invisible match if exists
+                        if let Some(idx) = candidates
+                            .iter()
+                            .position(|v: &ImportSuggestion| v.did == did && !v.accessible)
+                        {
+                            candidates.remove(idx);
                         }
+                    }
 
-                        if candidates.iter().all(|v: &ImportSuggestion| v.did != did) {
-                            // See if we're recommending TryFrom, TryInto, or FromIterator and add
-                            // a note about editions
-                            let note = if let Some(did) = did {
-                                let requires_note = !did.is_local()
-                                    && this.tcx.get_attrs(did, sym::rustc_diagnostic_item).any(
-                                        |attr| {
-                                            [sym::TryInto, sym::TryFrom, sym::FromIterator]
-                                                .map(|x| Some(x))
-                                                .contains(&attr.value_str())
-                                        },
-                                    );
-
-                                requires_note.then(|| {
-                                    format!(
-                                        "'{}' is included in the prelude starting in Edition 2021",
-                                        path_names_to_string(&path)
-                                    )
-                                })
-                            } else {
-                                None
-                            };
-
-                            candidates.push(ImportSuggestion {
-                                did,
-                                descr: res.descr(),
-                                path,
-                                accessible: child_accessible,
-                                doc_visible: child_doc_visible,
-                                note,
-                                via_import,
-                            });
-                        }
+                    if candidates.iter().all(|v: &ImportSuggestion| v.did != did) {
+                        // See if we're recommending TryFrom, TryInto, or FromIterator and add
+                        // a note about editions
+                        let note = if let Some(did) = did {
+                            let requires_note = !did.is_local()
+                                && this.tcx.get_attrs(did, sym::rustc_diagnostic_item).any(
+                                    |attr| {
+                                        [sym::TryInto, sym::TryFrom, sym::FromIterator]
+                                            .map(|x| Some(x))
+                                            .contains(&attr.value_str())
+                                    },
+                                );
+
+                            requires_note.then(|| {
+                                format!(
+                                    "'{}' is included in the prelude starting in Edition 2021",
+                                    path_names_to_string(&path)
+                                )
+                            })
+                        } else {
+                            None
+                        };
+
+                        candidates.push(ImportSuggestion {
+                            did,
+                            descr: res.descr(),
+                            path,
+                            accessible: child_accessible,
+                            doc_visible: child_doc_visible,
+                            note,
+                            via_import,
+                        });
                     }
                 }
 
diff --git a/compiler/rustc_resolve/src/ident.rs b/compiler/rustc_resolve/src/ident.rs
index 87f8e51f282..7f2bf03bcd1 100644
--- a/compiler/rustc_resolve/src/ident.rs
+++ b/compiler/rustc_resolve/src/ident.rs
@@ -958,12 +958,12 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
                 });
             }
 
-            if !restricted_shadowing && binding.expansion != LocalExpnId::ROOT {
-                if let NameBindingKind::Import { import, .. } = binding.kind
-                    && matches!(import.kind, ImportKind::MacroExport)
-                {
-                    self.macro_expanded_macro_export_errors.insert((path_span, binding.span));
-                }
+            if !restricted_shadowing
+                && binding.expansion != LocalExpnId::ROOT
+                && let NameBindingKind::Import { import, .. } = binding.kind
+                && matches!(import.kind, ImportKind::MacroExport)
+            {
+                self.macro_expanded_macro_export_errors.insert((path_span, binding.span));
             }
 
             self.record_use(ident, binding, used);
diff --git a/compiler/rustc_resolve/src/late.rs b/compiler/rustc_resolve/src/late.rs
index 917cb81aa51..3d0771390ed 100644
--- a/compiler/rustc_resolve/src/late.rs
+++ b/compiler/rustc_resolve/src/late.rs
@@ -4781,16 +4781,14 @@ impl<'a: 'ast, 'b, 'ast, 'tcx> LateResolutionVisitor<'a, 'b, 'ast, 'tcx> {
                 if let Some(res) = res
                     && let Some(def_id) = res.opt_def_id()
                     && !def_id.is_local()
+                    && self.r.tcx.crate_types().contains(&CrateType::ProcMacro)
+                    && matches!(
+                        self.r.tcx.sess.opts.resolve_doc_links,
+                        ResolveDocLinks::ExportedMetadata
+                    )
                 {
-                    if self.r.tcx.crate_types().contains(&CrateType::ProcMacro)
-                        && matches!(
-                            self.r.tcx.sess.opts.resolve_doc_links,
-                            ResolveDocLinks::ExportedMetadata
-                        )
-                    {
-                        // Encoding foreign def ids in proc macro crate metadata will ICE.
-                        return None;
-                    }
+                    // Encoding foreign def ids in proc macro crate metadata will ICE.
+                    return None;
                 }
                 res
             });
diff --git a/compiler/rustc_resolve/src/late/diagnostics.rs b/compiler/rustc_resolve/src/late/diagnostics.rs
index 8f516c2db09..51102d59bfe 100644
--- a/compiler/rustc_resolve/src/late/diagnostics.rs
+++ b/compiler/rustc_resolve/src/late/diagnostics.rs
@@ -2255,25 +2255,24 @@ impl<'a: 'ast, 'ast, 'tcx> LateResolutionVisitor<'a, '_, 'ast, 'tcx> {
     fn let_binding_suggestion(&mut self, err: &mut Diag<'_>, ident_span: Span) -> bool {
         if let Some(Expr { kind: ExprKind::Assign(lhs, ..), .. }) = self.diag_metadata.in_assignment
             && let ast::ExprKind::Path(None, ref path) = lhs.kind
+            && !ident_span.from_expansion()
         {
-            if !ident_span.from_expansion() {
-                let (span, text) = match path.segments.first() {
-                    Some(seg) if let Some(name) = seg.ident.as_str().strip_prefix("let") => {
-                        // a special case for #117894
-                        let name = name.strip_prefix('_').unwrap_or(name);
-                        (ident_span, format!("let {name}"))
-                    }
-                    _ => (ident_span.shrink_to_lo(), "let ".to_string()),
-                };
+            let (span, text) = match path.segments.first() {
+                Some(seg) if let Some(name) = seg.ident.as_str().strip_prefix("let") => {
+                    // a special case for #117894
+                    let name = name.strip_prefix('_').unwrap_or(name);
+                    (ident_span, format!("let {name}"))
+                }
+                _ => (ident_span.shrink_to_lo(), "let ".to_string()),
+            };
 
-                err.span_suggestion_verbose(
-                    span,
-                    "you might have meant to introduce a new binding",
-                    text,
-                    Applicability::MaybeIncorrect,
-                );
-                return true;
-            }
+            err.span_suggestion_verbose(
+                span,
+                "you might have meant to introduce a new binding",
+                text,
+                Applicability::MaybeIncorrect,
+            );
+            return true;
         }
         false
     }
diff --git a/compiler/rustc_trait_selection/src/traits/select/candidate_assembly.rs b/compiler/rustc_trait_selection/src/traits/select/candidate_assembly.rs
index 77efc2fc2db..66dfa283d07 100644
--- a/compiler/rustc_trait_selection/src/traits/select/candidate_assembly.rs
+++ b/compiler/rustc_trait_selection/src/traits/select/candidate_assembly.rs
@@ -513,10 +513,9 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
         // then there's nothing else to check.
         if let Some(closure_kind) = self_ty.to_opt_closure_kind()
             && let Some(goal_kind) = target_kind_ty.to_opt_closure_kind()
+            && closure_kind.extends(goal_kind)
         {
-            if closure_kind.extends(goal_kind) {
-                candidates.vec.push(AsyncFnKindHelperCandidate);
-            }
+            candidates.vec.push(AsyncFnKindHelperCandidate);
         }
     }
 
diff --git a/compiler/rustc_trait_selection/src/traits/select/mod.rs b/compiler/rustc_trait_selection/src/traits/select/mod.rs
index 241c3a3d141..f5cd7273ca2 100644
--- a/compiler/rustc_trait_selection/src/traits/select/mod.rs
+++ b/compiler/rustc_trait_selection/src/traits/select/mod.rs
@@ -1334,16 +1334,14 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
             return;
         }
 
-        if self.can_use_global_caches(param_env) {
-            if !trait_pred.has_infer() {
-                debug!(?trait_pred, ?result, "insert_evaluation_cache global");
-                // This may overwrite the cache with the same value
-                // FIXME: Due to #50507 this overwrites the different values
-                // This should be changed to use HashMapExt::insert_same
-                // when that is fixed
-                self.tcx().evaluation_cache.insert((param_env, trait_pred), dep_node, result);
-                return;
-            }
+        if self.can_use_global_caches(param_env) && !trait_pred.has_infer() {
+            debug!(?trait_pred, ?result, "insert_evaluation_cache global");
+            // This may overwrite the cache with the same value
+            // FIXME: Due to #50507 this overwrites the different values
+            // This should be changed to use HashMapExt::insert_same
+            // when that is fixed
+            self.tcx().evaluation_cache.insert((param_env, trait_pred), dep_node, result);
+            return;
         }
 
         debug!(?trait_pred, ?result, "insert_evaluation_cache");
@@ -1584,13 +1582,11 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
         if self.can_use_global_caches(param_env) {
             if let Err(Overflow(OverflowError::Canonical)) = candidate {
                 // Don't cache overflow globally; we only produce this in certain modes.
-            } else if !pred.has_infer() {
-                if !candidate.has_infer() {
-                    debug!(?pred, ?candidate, "insert_candidate_cache global");
-                    // This may overwrite the cache with the same value.
-                    tcx.selection_cache.insert((param_env, pred), dep_node, candidate);
-                    return;
-                }
+            } else if !pred.has_infer() && !candidate.has_infer() {
+                debug!(?pred, ?candidate, "insert_candidate_cache global");
+                // This may overwrite the cache with the same value.
+                tcx.selection_cache.insert((param_env, pred), dep_node, candidate);
+                return;
             }
         }
 
@@ -1980,10 +1976,10 @@ impl<'tcx> SelectionContext<'_, 'tcx> {
                 // impls have to be always applicable, meaning that the only allowed
                 // region constraints may be constraints also present on the default impl.
                 let tcx = self.tcx();
-                if other.evaluation.must_apply_modulo_regions() {
-                    if tcx.specializes((other_def, victim_def)) {
-                        return DropVictim::Yes;
-                    }
+                if other.evaluation.must_apply_modulo_regions()
+                    && tcx.specializes((other_def, victim_def))
+                {
+                    return DropVictim::Yes;
                 }
 
                 match tcx.impls_are_allowed_to_overlap(other_def, victim_def) {
diff --git a/compiler/rustc_ty_utils/src/opaque_types.rs b/compiler/rustc_ty_utils/src/opaque_types.rs
index e899284674c..6b24929467b 100644
--- a/compiler/rustc_ty_utils/src/opaque_types.rs
+++ b/compiler/rustc_ty_utils/src/opaque_types.rs
@@ -143,10 +143,8 @@ impl<'tcx> OpaqueTypeCollector<'tcx> {
         match origin {
             rustc_hir::OpaqueTyOrigin::FnReturn(_) | rustc_hir::OpaqueTyOrigin::AsyncFn(_) => {}
             rustc_hir::OpaqueTyOrigin::TyAlias { in_assoc_ty, .. } => {
-                if !in_assoc_ty {
-                    if !self.check_tait_defining_scope(alias_ty.def_id.expect_local()) {
-                        return;
-                    }
+                if !in_assoc_ty && !self.check_tait_defining_scope(alias_ty.def_id.expect_local()) {
+                    return;
                 }
             }
         }