Store patterns desugared from destructuring assignments in source map

And few more fixups.

I was worried this will lead to more memory usage since `ExprOrPatId` is double the size of `ExprId`, but this does not regress `analysis-stats .`. If this turns out to be a problem, we can easily use the high bit to encode this information.

16 files changed, 280 insertions, 174 deletions

diff --git a/src/tools/rust-analyzer/crates/hir-def/src/body.rs b/src/tools/rust-analyzer/crates/hir-def/src/body.rs
index d843ac1cad2..684eaf1c3b0 100644
--- a/src/tools/rust-analyzer/crates/hir-def/src/body.rs
+++ b/src/tools/rust-analyzer/crates/hir-def/src/body.rs
@@ -10,6 +10,7 @@ use std::ops::{Deref, Index};
 
 use base_db::CrateId;
 use cfg::{CfgExpr, CfgOptions};
+use either::Either;
 use hir_expand::{name::Name, ExpandError, InFile};
 use la_arena::{Arena, ArenaMap, Idx, RawIdx};
 use rustc_hash::FxHashMap;
@@ -22,8 +23,8 @@ use crate::{
     db::DefDatabase,
     expander::Expander,
     hir::{
-        dummy_expr_id, Array, AsmOperand, Binding, BindingId, Expr, ExprId, Label, LabelId, Pat,
-        PatId, RecordFieldPat, Statement,
+        dummy_expr_id, Array, AsmOperand, Binding, BindingId, Expr, ExprId, ExprOrPatId, Label,
+        LabelId, Pat, PatId, RecordFieldPat, Statement,
     },
     item_tree::AttrOwner,
     nameres::DefMap,
@@ -68,9 +69,12 @@ pub type LabelSource = InFile<LabelPtr>;
 pub type FieldPtr = AstPtr<ast::RecordExprField>;
 pub type FieldSource = InFile<FieldPtr>;
 
-pub type PatFieldPtr = AstPtr<ast::RecordPatField>;
+pub type PatFieldPtr = AstPtr<Either<ast::RecordExprField, ast::RecordPatField>>;
 pub type PatFieldSource = InFile<PatFieldPtr>;
 
+pub type ExprOrPatPtr = AstPtr<Either<ast::Expr, ast::Pat>>;
+pub type ExprOrPatSource = InFile<ExprOrPatPtr>;
+
 /// An item body together with the mapping from syntax nodes to HIR expression
 /// IDs. This is needed to go from e.g. a position in a file to the HIR
 /// expression containing it; but for type inference etc., we want to operate on
@@ -84,11 +88,13 @@ pub type PatFieldSource = InFile<PatFieldPtr>;
 /// this properly for macros.
 #[derive(Default, Debug, Eq, PartialEq)]
 pub struct BodySourceMap {
-    expr_map: FxHashMap<ExprSource, ExprId>,
+    // AST expressions can create patterns in destructuring assignments. Therefore, `ExprSource` can also map
+    // to `PatId`, and `PatId` can also map to `ExprSource` (the other way around is unaffected).
+    expr_map: FxHashMap<ExprSource, ExprOrPatId>,
     expr_map_back: ArenaMap<ExprId, ExprSource>,
 
     pat_map: FxHashMap<PatSource, PatId>,
-    pat_map_back: ArenaMap<PatId, PatSource>,
+    pat_map_back: ArenaMap<PatId, ExprOrPatSource>,
 
     label_map: FxHashMap<LabelSource, LabelId>,
     label_map_back: ArenaMap<LabelId, LabelSource>,
@@ -372,7 +378,7 @@ impl Body {
                             if let &Some(expr) = else_branch {
                                 f(expr);
                             }
-                            walk_exprs_in_pat(self, *pat, &mut f);
+                            self.walk_exprs_in_pat(*pat, &mut f);
                         }
                         Statement::Expr { expr: expression, .. } => f(*expression),
                         Statement::Item => (),
@@ -448,18 +454,18 @@ impl Body {
                 }
             },
             &Expr::Assignment { target, value } => {
-                walk_exprs_in_pat(self, target, &mut f);
+                self.walk_exprs_in_pat(target, &mut f);
                 f(value);
             }
         }
+    }
 
-        fn walk_exprs_in_pat(this: &Body, pat_id: PatId, f: &mut impl FnMut(ExprId)) {
-            this.walk_pats(pat_id, &mut |pat| {
-                if let Pat::Expr(expr) | Pat::ConstBlock(expr) = this[pat] {
-                    f(expr);
-                }
-            });
-        }
+    pub fn walk_exprs_in_pat(&self, pat_id: PatId, f: &mut impl FnMut(ExprId)) {
+        self.walk_pats(pat_id, &mut |pat| {
+            if let Pat::Expr(expr) | Pat::ConstBlock(expr) = self[pat] {
+                f(expr);
+            }
+        });
     }
 }
 
@@ -514,11 +520,18 @@ impl Index<BindingId> for Body {
 // FIXME: Change `node_` prefix to something more reasonable.
 // Perhaps `expr_syntax` and `expr_id`?
 impl BodySourceMap {
+    pub fn expr_or_pat_syntax(&self, id: ExprOrPatId) -> Result<ExprOrPatSource, SyntheticSyntax> {
+        match id {
+            ExprOrPatId::ExprId(id) => self.expr_syntax(id).map(|it| it.map(AstPtr::wrap_left)),
+            ExprOrPatId::PatId(id) => self.pat_syntax(id),
+        }
+    }
+
     pub fn expr_syntax(&self, expr: ExprId) -> Result<ExprSource, SyntheticSyntax> {
         self.expr_map_back.get(expr).cloned().ok_or(SyntheticSyntax)
     }
 
-    pub fn node_expr(&self, node: InFile<&ast::Expr>) -> Option<ExprId> {
+    pub fn node_expr(&self, node: InFile<&ast::Expr>) -> Option<ExprOrPatId> {
         let src = node.map(AstPtr::new);
         self.expr_map.get(&src).cloned()
     }
@@ -534,7 +547,7 @@ impl BodySourceMap {
         self.expansions.iter().map(|(&a, &b)| (a, b))
     }
 
-    pub fn pat_syntax(&self, pat: PatId) -> Result<PatSource, SyntheticSyntax> {
+    pub fn pat_syntax(&self, pat: PatId) -> Result<ExprOrPatSource, SyntheticSyntax> {
         self.pat_map_back.get(pat).cloned().ok_or(SyntheticSyntax)
     }
 
@@ -567,7 +580,7 @@ impl BodySourceMap {
         self.pat_field_map_back[&pat]
     }
 
-    pub fn macro_expansion_expr(&self, node: InFile<&ast::MacroExpr>) -> Option<ExprId> {
+    pub fn macro_expansion_expr(&self, node: InFile<&ast::MacroExpr>) -> Option<ExprOrPatId> {
         let src = node.map(AstPtr::new).map(AstPtr::upcast::<ast::MacroExpr>).map(AstPtr::upcast);
         self.expr_map.get(&src).copied()
     }
@@ -583,7 +596,11 @@ impl BodySourceMap {
         node: InFile<&ast::FormatArgsExpr>,
     ) -> Option<&[(syntax::TextRange, Name)]> {
         let src = node.map(AstPtr::new).map(AstPtr::upcast::<ast::Expr>);
-        self.template_map.as_ref()?.0.get(self.expr_map.get(&src)?).map(std::ops::Deref::deref)
+        self.template_map
+            .as_ref()?
+            .0
+            .get(&self.expr_map.get(&src)?.as_expr()?)
+            .map(std::ops::Deref::deref)
     }
 
     pub fn asm_template_args(
@@ -591,8 +608,8 @@ impl BodySourceMap {
         node: InFile<&ast::AsmExpr>,
     ) -> Option<(ExprId, &[Vec<(syntax::TextRange, usize)>])> {
         let src = node.map(AstPtr::new).map(AstPtr::upcast::<ast::Expr>);
-        let expr = self.expr_map.get(&src)?;
-        Some(*expr).zip(self.template_map.as_ref()?.1.get(expr).map(std::ops::Deref::deref))
+        let expr = self.expr_map.get(&src)?.as_expr()?;
+        Some(expr).zip(self.template_map.as_ref()?.1.get(&expr).map(std::ops::Deref::deref))
     }
 
     /// Get a reference to the body source map's diagnostics.
diff --git a/src/tools/rust-analyzer/crates/hir-def/src/body/lower.rs b/src/tools/rust-analyzer/crates/hir-def/src/body/lower.rs
index 3dff6ecd756..4b74028b83a 100644
--- a/src/tools/rust-analyzer/crates/hir-def/src/body/lower.rs
+++ b/src/tools/rust-analyzer/crates/hir-def/src/body/lower.rs
@@ -424,7 +424,7 @@ impl ExprCollector<'_> {
                 let inner = self.collect_expr_opt(e.expr());
                 // make the paren expr point to the inner expression as well for IDE resolution
                 let src = self.expander.in_file(syntax_ptr);
-                self.source_map.expr_map.insert(src, inner);
+                self.source_map.expr_map.insert(src, inner.into());
                 inner
             }
             ast::Expr::ReturnExpr(e) => {
@@ -660,7 +660,7 @@ impl ExprCollector<'_> {
                         // Make the macro-call point to its expanded expression so we can query
                         // semantics on syntax pointers to the macro
                         let src = self.expander.in_file(syntax_ptr);
-                        self.source_map.expr_map.insert(src, id);
+                        self.source_map.expr_map.insert(src, id.into());
                         id
                     }
                     None => self.alloc_expr(Expr::Missing, syntax_ptr),
@@ -686,9 +686,12 @@ impl ExprCollector<'_> {
 
     fn collect_expr_as_pat(&mut self, expr: ast::Expr) -> PatId {
         self.maybe_collect_expr_as_pat(&expr).unwrap_or_else(|| {
-            let syntax_ptr = AstPtr::new(&expr);
+            let src = self.expander.in_file(AstPtr::new(&expr).wrap_left());
             let expr = self.collect_expr(expr);
-            self.alloc_pat_from_expr(Pat::Expr(expr), syntax_ptr)
+            // Do not use `alloc_pat_from_expr()` here, it will override the entry in `expr_map`.
+            let id = self.body.pats.alloc(Pat::Expr(expr));
+            self.source_map.pat_map_back.insert(id, src);
+            id
         })
     }
 
@@ -743,16 +746,12 @@ impl ExprCollector<'_> {
             ast::Expr::MacroExpr(e) => {
                 let e = e.macro_call()?;
                 let macro_ptr = AstPtr::new(&e);
+                let src = self.expander.in_file(AstPtr::new(expr));
                 let id = self.collect_macro_call(e, macro_ptr, true, |this, expansion| {
-                    expansion.map(|it| this.collect_expr_as_pat(it))
+                    this.collect_expr_as_pat_opt(expansion)
                 });
-                match id {
-                    Some(id) => {
-                        // FIXME: Insert pat into source map.
-                        id
-                    }
-                    None => self.alloc_pat_from_expr(Pat::Missing, syntax_ptr),
-                }
+                self.source_map.expr_map.insert(src, id.into());
+                id
             }
             ast::Expr::RecordExpr(e) => {
                 let path =
@@ -767,9 +766,8 @@ impl ExprCollector<'_> {
                         let field_expr = f.expr()?;
                         let pat = self.collect_expr_as_pat(field_expr);
                         let name = f.field_name()?.as_name();
-                        // FIXME: Enable this.
-                        // let src = self.expander.in_file(AstPtr::new(&f));
-                        // self.source_map.pat_field_map_back.insert(pat, src);
+                        let src = self.expander.in_file(AstPtr::new(&f).wrap_left());
+                        self.source_map.pat_field_map_back.insert(pat, src);
                         Some(RecordFieldPat { name, pat })
                     })
                     .collect();
@@ -813,7 +811,10 @@ impl ExprCollector<'_> {
                                 None => Either::Left(this.missing_pat()),
                             },
                         );
-                        // FIXME: Insert pat into source map.
+                        if let Either::Left(pat) = pat {
+                            let src = this.expander.in_file(AstPtr::new(&expr).wrap_left());
+                            this.source_map.pat_map_back.insert(pat, src);
+                        }
                         pat
                     }
                     None => {
@@ -1236,7 +1237,7 @@ impl ExprCollector<'_> {
             // Make the macro-call point to its expanded expression so we can query
             // semantics on syntax pointers to the macro
             let src = self.expander.in_file(syntax_ptr);
-            self.source_map.expr_map.insert(src, tail);
+            self.source_map.expr_map.insert(src, tail.into());
         })
     }
 
@@ -1500,7 +1501,7 @@ impl ExprCollector<'_> {
                         let ast_pat = f.pat()?;
                         let pat = self.collect_pat(ast_pat, binding_list);
                         let name = f.field_name()?.as_name();
-                        let src = self.expander.in_file(AstPtr::new(&f));
+                        let src = self.expander.in_file(AstPtr::new(&f).wrap_right());
                         self.source_map.pat_field_map_back.insert(pat, src);
                         Some(RecordFieldPat { name, pat })
                     })
@@ -2187,7 +2188,7 @@ impl ExprCollector<'_> {
         let src = self.expander.in_file(ptr);
         let id = self.body.exprs.alloc(expr);
         self.source_map.expr_map_back.insert(id, src);
-        self.source_map.expr_map.insert(src, id);
+        self.source_map.expr_map.insert(src, id.into());
         id
     }
     // FIXME: desugared exprs don't have ptr, that's wrong and should be fixed.
@@ -2215,14 +2216,17 @@ impl ExprCollector<'_> {
         binding
     }
 
-    fn alloc_pat_from_expr(&mut self, pat: Pat, _ptr: ExprPtr) -> PatId {
-        // FIXME: Insert into source map.
-        self.body.pats.alloc(pat)
+    fn alloc_pat_from_expr(&mut self, pat: Pat, ptr: ExprPtr) -> PatId {
+        let src = self.expander.in_file(ptr);
+        let id = self.body.pats.alloc(pat);
+        self.source_map.expr_map.insert(src, id.into());
+        self.source_map.pat_map_back.insert(id, src.map(AstPtr::wrap_left));
+        id
     }
     fn alloc_pat(&mut self, pat: Pat, ptr: PatPtr) -> PatId {
         let src = self.expander.in_file(ptr);
         let id = self.body.pats.alloc(pat);
-        self.source_map.pat_map_back.insert(id, src);
+        self.source_map.pat_map_back.insert(id, src.map(AstPtr::wrap_right));
         self.source_map.pat_map.insert(src, id);
         id
     }
diff --git a/src/tools/rust-analyzer/crates/hir-def/src/body/scope.rs b/src/tools/rust-analyzer/crates/hir-def/src/body/scope.rs
index 56d6ed23309..c6967961b33 100644
--- a/src/tools/rust-analyzer/crates/hir-def/src/body/scope.rs
+++ b/src/tools/rust-analyzer/crates/hir-def/src/body/scope.rs
@@ -333,6 +333,8 @@ mod tests {
 
         let expr_id = source_map
             .node_expr(InFile { file_id: file_id.into(), value: &marker.into() })
+            .unwrap()
+            .as_expr()
             .unwrap();
         let scope = scopes.scope_for(expr_id);
 
@@ -488,8 +490,11 @@ fn foo() {
 
         let expr_scope = {
             let expr_ast = name_ref.syntax().ancestors().find_map(ast::Expr::cast).unwrap();
-            let expr_id =
-                source_map.node_expr(InFile { file_id: file_id.into(), value: &expr_ast }).unwrap();
+            let expr_id = source_map
+                .node_expr(InFile { file_id: file_id.into(), value: &expr_ast })
+                .unwrap()
+                .as_expr()
+                .unwrap();
             scopes.scope_for(expr_id).unwrap()
         };
 
diff --git a/src/tools/rust-analyzer/crates/hir-def/src/hir.rs b/src/tools/rust-analyzer/crates/hir-def/src/hir.rs
index 3c62b04f97e..a575a2d1991 100644
--- a/src/tools/rust-analyzer/crates/hir-def/src/hir.rs
+++ b/src/tools/rust-analyzer/crates/hir-def/src/hir.rs
@@ -48,6 +48,22 @@ pub enum ExprOrPatId {
     ExprId(ExprId),
     PatId(PatId),
 }
+
+impl ExprOrPatId {
+    pub fn as_expr(self) -> Option<ExprId> {
+        match self {
+            Self::ExprId(v) => Some(v),
+            _ => None,
+        }
+    }
+
+    pub fn as_pat(self) -> Option<PatId> {
+        match self {
+            Self::PatId(v) => Some(v),
+            _ => None,
+        }
+    }
+}
 stdx::impl_from!(ExprId, PatId for ExprOrPatId);
 
 #[derive(Debug, Clone, Eq, PartialEq)]
diff --git a/src/tools/rust-analyzer/crates/hir-def/src/test_db.rs b/src/tools/rust-analyzer/crates/hir-def/src/test_db.rs
index 4db21eb46bd..0c36c88fb09 100644
--- a/src/tools/rust-analyzer/crates/hir-def/src/test_db.rs
+++ b/src/tools/rust-analyzer/crates/hir-def/src/test_db.rs
@@ -198,7 +198,10 @@ impl TestDB {
             .filter_map(|node| {
                 let block = ast::BlockExpr::cast(node)?;
                 let expr = ast::Expr::from(block);
-                let expr_id = source_map.node_expr(InFile::new(position.file_id.into(), &expr))?;
+                let expr_id = source_map
+                    .node_expr(InFile::new(position.file_id.into(), &expr))?
+                    .as_expr()
+                    .unwrap();
                 let scope = scopes.scope_for(expr_id).unwrap();
                 Some(scope)
             });
diff --git a/src/tools/rust-analyzer/crates/hir-ty/src/diagnostics/unsafe_check.rs b/src/tools/rust-analyzer/crates/hir-ty/src/diagnostics/unsafe_check.rs
index f610c9e96c8..492262c7a4c 100644
--- a/src/tools/rust-analyzer/crates/hir-ty/src/diagnostics/unsafe_check.rs
+++ b/src/tools/rust-analyzer/crates/hir-ty/src/diagnostics/unsafe_check.rs
@@ -3,7 +3,7 @@
 
 use hir_def::{
     body::Body,
-    hir::{Expr, ExprId, UnaryOp},
+    hir::{Expr, ExprId, ExprOrPatId, Pat, UnaryOp},
     resolver::{resolver_for_expr, ResolveValueResult, Resolver, ValueNs},
     type_ref::Rawness,
     DefWithBodyId,
@@ -16,7 +16,7 @@ use crate::{
 /// Returns `(unsafe_exprs, fn_is_unsafe)`.
 ///
 /// If `fn_is_unsafe` is false, `unsafe_exprs` are hard errors. If true, they're `unsafe_op_in_unsafe_fn`.
-pub fn missing_unsafe(db: &dyn HirDatabase, def: DefWithBodyId) -> (Vec<ExprId>, bool) {
+pub fn missing_unsafe(db: &dyn HirDatabase, def: DefWithBodyId) -> (Vec<ExprOrPatId>, bool) {
     let _p = tracing::info_span!("missing_unsafe").entered();
 
     let mut res = Vec::new();
@@ -32,7 +32,7 @@ pub fn missing_unsafe(db: &dyn HirDatabase, def: DefWithBodyId) -> (Vec<ExprId>,
     let infer = db.infer(def);
     unsafe_expressions(db, &infer, def, &body, body.body_expr, &mut |expr| {
         if !expr.inside_unsafe_block {
-            res.push(expr.expr);
+            res.push(expr.node);
         }
     });
 
@@ -40,7 +40,7 @@ pub fn missing_unsafe(db: &dyn HirDatabase, def: DefWithBodyId) -> (Vec<ExprId>,
 }
 
 pub struct UnsafeExpr {
-    pub expr: ExprId,
+    pub node: ExprOrPatId,
     pub inside_unsafe_block: bool,
 }
 
@@ -75,26 +75,28 @@ fn walk_unsafe(
     inside_unsafe_block: bool,
     unsafe_expr_cb: &mut dyn FnMut(UnsafeExpr),
 ) {
+    let mut mark_unsafe_path = |path, node| {
+        let g = resolver.update_to_inner_scope(db.upcast(), def, current);
+        let value_or_partial = resolver.resolve_path_in_value_ns(db.upcast(), path);
+        if let Some(ResolveValueResult::ValueNs(ValueNs::StaticId(id), _)) = value_or_partial {
+            let static_data = db.static_data(id);
+            if static_data.mutable || (static_data.is_extern && !static_data.has_safe_kw) {
+                unsafe_expr_cb(UnsafeExpr { node, inside_unsafe_block });
+            }
+        }
+        resolver.reset_to_guard(g);
+    };
+
     let expr = &body.exprs[current];
     match expr {
         &Expr::Call { callee, .. } => {
             if let Some(func) = infer[callee].as_fn_def(db) {
                 if is_fn_unsafe_to_call(db, func) {
-                    unsafe_expr_cb(UnsafeExpr { expr: current, inside_unsafe_block });
-                }
-            }
-        }
-        Expr::Path(path) => {
-            let g = resolver.update_to_inner_scope(db.upcast(), def, current);
-            let value_or_partial = resolver.resolve_path_in_value_ns(db.upcast(), path);
-            if let Some(ResolveValueResult::ValueNs(ValueNs::StaticId(id), _)) = value_or_partial {
-                let static_data = db.static_data(id);
-                if static_data.mutable || (static_data.is_extern && !static_data.has_safe_kw) {
-                    unsafe_expr_cb(UnsafeExpr { expr: current, inside_unsafe_block });
+                    unsafe_expr_cb(UnsafeExpr { node: current.into(), inside_unsafe_block });
                 }
             }
-            resolver.reset_to_guard(g);
         }
+        Expr::Path(path) => mark_unsafe_path(path, current.into()),
         Expr::Ref { expr, rawness: Rawness::RawPtr, mutability: _ } => {
             if let Expr::Path(_) = body.exprs[*expr] {
                 // Do not report unsafe for `addr_of[_mut]!(EXTERN_OR_MUT_STATIC)`,
@@ -108,12 +110,12 @@ fn walk_unsafe(
                 .map(|(func, _)| is_fn_unsafe_to_call(db, func))
                 .unwrap_or(false)
             {
-                unsafe_expr_cb(UnsafeExpr { expr: current, inside_unsafe_block });
+                unsafe_expr_cb(UnsafeExpr { node: current.into(), inside_unsafe_block });
             }
         }
         Expr::UnaryOp { expr, op: UnaryOp::Deref } => {
             if let TyKind::Raw(..) = &infer[*expr].kind(Interner) {
-                unsafe_expr_cb(UnsafeExpr { expr: current, inside_unsafe_block });
+                unsafe_expr_cb(UnsafeExpr { node: current.into(), inside_unsafe_block });
             }
         }
         Expr::Unsafe { .. } => {
@@ -121,6 +123,13 @@ fn walk_unsafe(
                 walk_unsafe(db, infer, body, resolver, def, child, true, unsafe_expr_cb);
             });
         }
+        &Expr::Assignment { target, value: _ } => {
+            body.walk_pats(target, &mut |pat| {
+                if let Pat::Path(path) = &body[pat] {
+                    mark_unsafe_path(path, pat.into());
+                }
+            });
+        }
         _ => {}
     }
 
diff --git a/src/tools/rust-analyzer/crates/hir-ty/src/infer.rs b/src/tools/rust-analyzer/crates/hir-ty/src/infer.rs
index f2c860c9eb7..db16899d9f9 100644
--- a/src/tools/rust-analyzer/crates/hir-ty/src/infer.rs
+++ b/src/tools/rust-analyzer/crates/hir-ty/src/infer.rs
@@ -482,12 +482,27 @@ impl InferenceResult {
     pub fn variant_resolution_for_pat(&self, id: PatId) -> Option<VariantId> {
         self.variant_resolutions.get(&id.into()).copied()
     }
+    pub fn variant_resolution_for_expr_or_pat(&self, id: ExprOrPatId) -> Option<VariantId> {
+        match id {
+            ExprOrPatId::ExprId(id) => self.variant_resolution_for_expr(id),
+            ExprOrPatId::PatId(id) => self.variant_resolution_for_pat(id),
+        }
+    }
     pub fn assoc_resolutions_for_expr(&self, id: ExprId) -> Option<(AssocItemId, Substitution)> {
         self.assoc_resolutions.get(&id.into()).cloned()
     }
     pub fn assoc_resolutions_for_pat(&self, id: PatId) -> Option<(AssocItemId, Substitution)> {
         self.assoc_resolutions.get(&id.into()).cloned()
     }
+    pub fn assoc_resolutions_for_expr_or_pat(
+        &self,
+        id: ExprOrPatId,
+    ) -> Option<(AssocItemId, Substitution)> {
+        match id {
+            ExprOrPatId::ExprId(id) => self.assoc_resolutions_for_expr(id),
+            ExprOrPatId::PatId(id) => self.assoc_resolutions_for_pat(id),
+        }
+    }
     pub fn type_mismatch_for_expr(&self, expr: ExprId) -> Option<&TypeMismatch> {
         self.type_mismatches.get(&expr.into())
     }
@@ -506,6 +521,12 @@ impl InferenceResult {
     pub fn closure_info(&self, closure: &ClosureId) -> &(Vec<CapturedItem>, FnTrait) {
         self.closure_info.get(closure).unwrap()
     }
+    pub fn type_of_expr_or_pat(&self, id: ExprOrPatId) -> Option<&Ty> {
+        match id {
+            ExprOrPatId::ExprId(id) => self.type_of_expr.get(id),
+            ExprOrPatId::PatId(id) => self.type_of_pat.get(id),
+        }
+    }
 }
 
 impl Index<ExprId> for InferenceResult {
@@ -524,6 +545,14 @@ impl Index<PatId> for InferenceResult {
     }
 }
 
+impl Index<ExprOrPatId> for InferenceResult {
+    type Output = Ty;
+
+    fn index(&self, id: ExprOrPatId) -> &Ty {
+        self.type_of_expr_or_pat(id).unwrap_or(&self.standard_types.unknown)
+    }
+}
+
 impl Index<BindingId> for InferenceResult {
     type Output = Ty;
 
diff --git a/src/tools/rust-analyzer/crates/hir-ty/src/tests/simple.rs b/src/tools/rust-analyzer/crates/hir-ty/src/tests/simple.rs
index a8170b60606..e6ef56b80d9 100644
--- a/src/tools/rust-analyzer/crates/hir-ty/src/tests/simple.rs
+++ b/src/tools/rust-analyzer/crates/hir-ty/src/tests/simple.rs
@@ -3418,11 +3418,11 @@ struct TS(usize);
 fn main() {
     let x;
     [x,] = &[1,];
-  //^^^^expected &'? [i32; 1], got [{unknown}; _]
+  //^^^^expected &'? [i32; 1], got [{unknown}]
 
     let x;
     [(x,),] = &[(1,),];
-  //^^^^^^^expected &'? [(i32,); 1], got [{unknown}; _]
+  //^^^^^^^expected &'? [(i32,); 1], got [{unknown}]
 
     let x;
     ((x,),) = &((1,),);
diff --git a/src/tools/rust-analyzer/crates/hir/src/diagnostics.rs b/src/tools/rust-analyzer/crates/hir/src/diagnostics.rs
index 24c1b80bdf1..2fedffe047d 100644
--- a/src/tools/rust-analyzer/crates/hir/src/diagnostics.rs
+++ b/src/tools/rust-analyzer/crates/hir/src/diagnostics.rs
@@ -257,7 +257,7 @@ pub struct PrivateField {
 
 #[derive(Debug)]
 pub struct MissingUnsafe {
-    pub expr: InFile<AstPtr<ast::Expr>>,
+    pub expr: InFile<AstPtr<Either<ast::Expr, ast::Pat>>>,
     /// If true, the diagnostics is an `unsafe_op_in_unsafe_fn` lint instead of a hard error.
     pub only_lint: bool,
 }
@@ -398,56 +398,46 @@ impl AnyDiagnostic {
                     .map(|idx| variant_data.fields()[idx].name.clone())
                     .collect();
 
-                match record {
-                    Either::Left(record_expr) => match source_map.expr_syntax(record_expr) {
-                        Ok(source_ptr) => {
-                            let root = source_ptr.file_syntax(db.upcast());
-                            if let ast::Expr::RecordExpr(record_expr) =
-                                source_ptr.value.to_node(&root)
-                            {
-                                if record_expr.record_expr_field_list().is_some() {
-                                    let field_list_parent_path =
-                                        record_expr.path().map(|path| AstPtr::new(&path));
-                                    return Some(
-                                        MissingFields {
-                                            file: source_ptr.file_id,
-                                            field_list_parent: AstPtr::new(&Either::Left(
-                                                record_expr,
-                                            )),
-                                            field_list_parent_path,
-                                            missed_fields,
-                                        }
-                                        .into(),
-                                    );
+                let record = match record {
+                    Either::Left(record_expr) => {
+                        source_map.expr_syntax(record_expr).ok()?.map(AstPtr::wrap_left)
+                    }
+                    Either::Right(record_pat) => source_map.pat_syntax(record_pat).ok()?,
+                };
+                let file = record.file_id;
+                let root = record.file_syntax(db.upcast());
+                match record.value.to_node(&root) {
+                    Either::Left(ast::Expr::RecordExpr(record_expr)) => {
+                        if record_expr.record_expr_field_list().is_some() {
+                            let field_list_parent_path =
+                                record_expr.path().map(|path| AstPtr::new(&path));
+                            return Some(
+                                MissingFields {
+                                    file,
+                                    field_list_parent: AstPtr::new(&Either::Left(record_expr)),
+                                    field_list_parent_path,
+                                    missed_fields,
                                 }
-                            }
+                                .into(),
+                            );
                         }
-                        Err(SyntheticSyntax) => (),
-                    },
-                    Either::Right(record_pat) => match source_map.pat_syntax(record_pat) {
-                        Ok(source_ptr) => {
-                            if let Some(ptr) = source_ptr.value.cast::<ast::RecordPat>() {
-                                let root = source_ptr.file_syntax(db.upcast());
-                                let record_pat = ptr.to_node(&root);
-                                if record_pat.record_pat_field_list().is_some() {
-                                    let field_list_parent_path =
-                                        record_pat.path().map(|path| AstPtr::new(&path));
-                                    return Some(
-                                        MissingFields {
-                                            file: source_ptr.file_id,
-                                            field_list_parent: AstPtr::new(&Either::Right(
-                                                record_pat,
-                                            )),
-                                            field_list_parent_path,
-                                            missed_fields,
-                                        }
-                                        .into(),
-                                    );
+                    }
+                    Either::Right(ast::Pat::RecordPat(record_pat)) => {
+                        if record_pat.record_pat_field_list().is_some() {
+                            let field_list_parent_path =
+                                record_pat.path().map(|path| AstPtr::new(&path));
+                            return Some(
+                                MissingFields {
+                                    file,
+                                    field_list_parent: AstPtr::new(&Either::Right(record_pat)),
+                                    field_list_parent_path,
+                                    missed_fields,
                                 }
-                            }
+                                .into(),
+                            );
                         }
-                        Err(SyntheticSyntax) => (),
-                    },
+                    }
+                    _ => {}
                 }
             }
             BodyValidationDiagnostic::ReplaceFilterMapNextWithFindMap { method_call_expr } => {
@@ -543,7 +533,7 @@ impl AnyDiagnostic {
         };
         let expr_or_pat_syntax = |id| match id {
             ExprOrPatId::ExprId(expr) => expr_syntax(expr).map(|it| it.map(AstPtr::wrap_left)),
-            ExprOrPatId::PatId(pat) => pat_syntax(pat).map(|it| it.map(AstPtr::wrap_right)),
+            ExprOrPatId::PatId(pat) => pat_syntax(pat),
         };
         Some(match d {
             &InferenceDiagnostic::NoSuchField { field: expr, private, variant } => {
@@ -551,9 +541,7 @@ impl AnyDiagnostic {
                     ExprOrPatId::ExprId(expr) => {
                         source_map.field_syntax(expr).map(AstPtr::wrap_left)
                     }
-                    ExprOrPatId::PatId(pat) => {
-                        source_map.pat_field_syntax(pat).map(AstPtr::wrap_right)
-                    }
+                    ExprOrPatId::PatId(pat) => source_map.pat_field_syntax(pat),
                 };
                 NoSuchField { field: expr_or_pat, private, variant }.into()
             }
diff --git a/src/tools/rust-analyzer/crates/hir/src/lib.rs b/src/tools/rust-analyzer/crates/hir/src/lib.rs
index 30e023e1a47..4a18795e7d6 100644
--- a/src/tools/rust-analyzer/crates/hir/src/lib.rs
+++ b/src/tools/rust-analyzer/crates/hir/src/lib.rs
@@ -1885,7 +1885,7 @@ impl DefWithBody {
 
         let (unafe_exprs, only_lint) = hir_ty::diagnostics::missing_unsafe(db, self.into());
         for expr in unafe_exprs {
-            match source_map.expr_syntax(expr) {
+            match source_map.expr_or_pat_syntax(expr) {
                 Ok(expr) => acc.push(MissingUnsafe { expr, only_lint }.into()),
                 Err(SyntheticSyntax) => {
                     // FIXME: Here and elsewhere in this file, the `expr` was
@@ -3481,7 +3481,7 @@ impl Local {
                     LocalSource {
                         local: self,
                         source: src.map(|ast| match ast.to_node(&root) {
-                            ast::Pat::IdentPat(it) => Either::Left(it),
+                            Either::Right(ast::Pat::IdentPat(it)) => Either::Left(it),
                             _ => unreachable!("local with non ident-pattern"),
                         }),
                     }
@@ -3510,7 +3510,7 @@ impl Local {
                     LocalSource {
                         local: self,
                         source: src.map(|ast| match ast.to_node(&root) {
-                            ast::Pat::IdentPat(it) => Either::Left(it),
+                            Either::Right(ast::Pat::IdentPat(it)) => Either::Left(it),
                             _ => unreachable!("local with non ident-pattern"),
                         }),
                     }
@@ -4235,10 +4235,7 @@ impl CaptureUsages {
                 }
                 mir::MirSpan::PatId(pat) => {
                     if let Ok(pat) = source_map.pat_syntax(pat) {
-                        result.push(CaptureUsageSource {
-                            is_ref,
-                            source: pat.map(AstPtr::wrap_right),
-                        });
+                        result.push(CaptureUsageSource { is_ref, source: pat });
                     }
                 }
                 mir::MirSpan::BindingId(binding) => result.extend(
@@ -4246,10 +4243,7 @@ impl CaptureUsages {
                         .patterns_for_binding(binding)
                         .iter()
                         .filter_map(|&pat| source_map.pat_syntax(pat).ok())
-                        .map(|pat| CaptureUsageSource {
-                            is_ref,
-                            source: pat.map(AstPtr::wrap_right),
-                        }),
+                        .map(|pat| CaptureUsageSource { is_ref, source: pat }),
                 ),
                 mir::MirSpan::SelfParam | mir::MirSpan::Unknown => {
                     unreachable!("invalid capture usage span")
diff --git a/src/tools/rust-analyzer/crates/hir/src/semantics.rs b/src/tools/rust-analyzer/crates/hir/src/semantics.rs
index b27f1fbb5db..d210c267143 100644
--- a/src/tools/rust-analyzer/crates/hir/src/semantics.rs
+++ b/src/tools/rust-analyzer/crates/hir/src/semantics.rs
@@ -11,7 +11,7 @@ use std::{
 
 use either::Either;
 use hir_def::{
-    hir::Expr,
+    hir::{Expr, ExprOrPatId},
     lower::LowerCtx,
     nameres::{MacroSubNs, ModuleOrigin},
     path::ModPath,
@@ -1755,7 +1755,9 @@ impl<'db> SemanticsImpl<'db> {
             }
 
             if let Some(parent) = ast::Expr::cast(parent.clone()) {
-                if let Some(expr_id) = source_map.node_expr(InFile { file_id, value: &parent }) {
+                if let Some(ExprOrPatId::ExprId(expr_id)) =
+                    source_map.node_expr(InFile { file_id, value: &parent })
+                {
                     if let Expr::Unsafe { .. } = body[expr_id] {
                         break true;
                     }
diff --git a/src/tools/rust-analyzer/crates/hir/src/semantics/source_to_def.rs b/src/tools/rust-analyzer/crates/hir/src/semantics/source_to_def.rs
index fd6d52d6c9d..e53a7da7edb 100644
--- a/src/tools/rust-analyzer/crates/hir/src/semantics/source_to_def.rs
+++ b/src/tools/rust-analyzer/crates/hir/src/semantics/source_to_def.rs
@@ -306,7 +306,7 @@ impl SourceToDefCtx<'_, '_> {
             .position(|it| it == *src.value)?;
         let container = self.find_pat_or_label_container(src.syntax_ref())?;
         let (_, source_map) = self.db.body_with_source_map(container);
-        let expr = source_map.node_expr(src.with_value(&ast::Expr::AsmExpr(asm)))?;
+        let expr = source_map.node_expr(src.with_value(&ast::Expr::AsmExpr(asm)))?.as_expr()?;
         Some(InlineAsmOperand { owner: container, expr, index })
     }
 
@@ -350,7 +350,8 @@ impl SourceToDefCtx<'_, '_> {
         let break_or_continue = ast::Expr::cast(src.value.syntax().parent()?)?;
         let container = self.find_pat_or_label_container(src.syntax_ref())?;
         let (body, source_map) = self.db.body_with_source_map(container);
-        let break_or_continue = source_map.node_expr(src.with_value(&break_or_continue))?;
+        let break_or_continue =
+            source_map.node_expr(src.with_value(&break_or_continue))?.as_expr()?;
         let (Expr::Break { label, .. } | Expr::Continue { label }) = body[break_or_continue] else {
             return None;
         };
diff --git a/src/tools/rust-analyzer/crates/hir/src/source_analyzer.rs b/src/tools/rust-analyzer/crates/hir/src/source_analyzer.rs
index 3da67ae23f8..f2f27517fd6 100644
--- a/src/tools/rust-analyzer/crates/hir/src/source_analyzer.rs
+++ b/src/tools/rust-analyzer/crates/hir/src/source_analyzer.rs
@@ -13,7 +13,7 @@ use hir_def::{
         scope::{ExprScopes, ScopeId},
         Body, BodySourceMap,
     },
-    hir::{BindingId, ExprId, Pat, PatId},
+    hir::{BindingId, ExprId, ExprOrPatId, Pat, PatId},
     lang_item::LangItem,
     lower::LowerCtx,
     nameres::MacroSubNs,
@@ -120,7 +120,7 @@ impl SourceAnalyzer {
         self.def.as_ref().map(|(_, body, _)| &**body)
     }
 
-    fn expr_id(&self, db: &dyn HirDatabase, expr: &ast::Expr) -> Option<ExprId> {
+    fn expr_id(&self, db: &dyn HirDatabase, expr: &ast::Expr) -> Option<ExprOrPatId> {
         let src = match expr {
             ast::Expr::MacroExpr(expr) => {
                 self.expand_expr(db, InFile::new(self.file_id, expr.macro_call()?))?.into()
@@ -174,7 +174,9 @@ impl SourceAnalyzer {
         db: &dyn HirDatabase,
         expr: &ast::Expr,
     ) -> Option<&[Adjustment]> {
-        let expr_id = self.expr_id(db, expr)?;
+        // It is safe to omit destructuring assignments here because they have no adjustments (neither
+        // expressions nor patterns).
+        let expr_id = self.expr_id(db, expr)?.as_expr()?;
         let infer = self.infer.as_ref()?;
         infer.expr_adjustments.get(&expr_id).map(|v| &**v)
     }
@@ -186,9 +188,9 @@ impl SourceAnalyzer {
     ) -> Option<(Type, Option<Type>)> {
         let expr_id = self.expr_id(db, expr)?;
         let infer = self.infer.as_ref()?;
-        let coerced = infer
-            .expr_adjustments
-            .get(&expr_id)
+        let coerced = expr_id
+            .as_expr()
+            .and_then(|expr_id| infer.expr_adjustments.get(&expr_id))
             .and_then(|adjusts| adjusts.last().map(|adjust| adjust.target.clone()));
         let ty = infer[expr_id].clone();
         let mk_ty = |ty| Type::new_with_resolver(db, &self.resolver, ty);
@@ -268,7 +270,7 @@ impl SourceAnalyzer {
         db: &dyn HirDatabase,
         call: &ast::MethodCallExpr,
     ) -> Option<Callable> {
-        let expr_id = self.expr_id(db, &call.clone().into())?;
+        let expr_id = self.expr_id(db, &call.clone().into())?.as_expr()?;
         let (func, substs) = self.infer.as_ref()?.method_resolution(expr_id)?;
         let ty = db.value_ty(func.into())?.substitute(Interner, &substs);
         let ty = Type::new_with_resolver(db, &self.resolver, ty);
@@ -282,7 +284,7 @@ impl SourceAnalyzer {
         db: &dyn HirDatabase,
         call: &ast::MethodCallExpr,
     ) -> Option<Function> {
-        let expr_id = self.expr_id(db, &call.clone().into())?;
+        let expr_id = self.expr_id(db, &call.clone().into())?.as_expr()?;
         let (f_in_trait, substs) = self.infer.as_ref()?.method_resolution(expr_id)?;
 
         Some(self.resolve_impl_method_or_trait_def(db, f_in_trait, substs).into())
@@ -293,7 +295,7 @@ impl SourceAnalyzer {
         db: &dyn HirDatabase,
         call: &ast::MethodCallExpr,
     ) -> Option<Either<Function, Field>> {
-        let expr_id = self.expr_id(db, &call.clone().into())?;
+        let expr_id = self.expr_id(db, &call.clone().into())?.as_expr()?;
         let inference_result = self.infer.as_ref()?;
         match inference_result.method_resolution(expr_id) {
             Some((f_in_trait, substs)) => Some(Either::Left(
@@ -322,7 +324,7 @@ impl SourceAnalyzer {
         field: &ast::FieldExpr,
     ) -> Option<Either<Field, TupleField>> {
         let &(def, ..) = self.def.as_ref()?;
-        let expr_id = self.expr_id(db, &field.clone().into())?;
+        let expr_id = self.expr_id(db, &field.clone().into())?.as_expr()?;
         self.infer.as_ref()?.field_resolution(expr_id).map(|it| {
             it.map_either(Into::into, |f| TupleField { owner: def, tuple: f.tuple, index: f.index })
         })
@@ -334,7 +336,7 @@ impl SourceAnalyzer {
         field: &ast::FieldExpr,
     ) -> Option<Either<Either<Field, TupleField>, Function>> {
         let &(def, ..) = self.def.as_ref()?;
-        let expr_id = self.expr_id(db, &field.clone().into())?;
+        let expr_id = self.expr_id(db, &field.clone().into())?.as_expr()?;
         let inference_result = self.infer.as_ref()?;
         match inference_result.field_resolution(expr_id) {
             Some(field) => Some(Either::Left(field.map_either(Into::into, |f| TupleField {
@@ -403,7 +405,7 @@ impl SourceAnalyzer {
                 self.infer
                     .as_ref()
                     .and_then(|infer| {
-                        let expr = self.expr_id(db, &prefix_expr.clone().into())?;
+                        let expr = self.expr_id(db, &prefix_expr.clone().into())?.as_expr()?;
                         let (func, _) = infer.method_resolution(expr)?;
                         let (deref_mut_trait, deref_mut) = self.lang_trait_fn(
                             db,
@@ -449,7 +451,7 @@ impl SourceAnalyzer {
             .infer
             .as_ref()
             .and_then(|infer| {
-                let expr = self.expr_id(db, &index_expr.clone().into())?;
+                let expr = self.expr_id(db, &index_expr.clone().into())?.as_expr()?;
                 let (func, _) = infer.method_resolution(expr)?;
                 let (index_mut_trait, index_mut_fn) = self.lang_trait_fn(
                     db,
@@ -537,8 +539,8 @@ impl SourceAnalyzer {
                 _ => None,
             }
         };
-        let (_, subst) = self.infer.as_ref()?.type_of_expr.get(expr_id)?.as_adt()?;
-        let variant = self.infer.as_ref()?.variant_resolution_for_expr(expr_id)?;
+        let (_, subst) = self.infer.as_ref()?.type_of_expr_or_pat(expr_id)?.as_adt()?;
+        let variant = self.infer.as_ref()?.variant_resolution_for_expr_or_pat(expr_id)?;
         let variant_data = variant.variant_data(db.upcast());
         let field = FieldId { parent: variant, local_id: variant_data.field(&local_name)? };
         let field_ty =
@@ -606,10 +608,10 @@ impl SourceAnalyzer {
             let infer = self.infer.as_deref()?;
             if let Some(path_expr) = parent().and_then(ast::PathExpr::cast) {
                 let expr_id = self.expr_id(db, &path_expr.into())?;
-                if let Some((assoc, subs)) = infer.assoc_resolutions_for_expr(expr_id) {
+                if let Some((assoc, subs)) = infer.assoc_resolutions_for_expr_or_pat(expr_id) {
                     let assoc = match assoc {
                         AssocItemId::FunctionId(f_in_trait) => {
-                            match infer.type_of_expr.get(expr_id) {
+                            match infer.type_of_expr_or_pat(expr_id) {
                                 None => assoc,
                                 Some(func_ty) => {
                                     if let TyKind::FnDef(_fn_def, subs) = func_ty.kind(Interner) {
@@ -634,7 +636,7 @@ impl SourceAnalyzer {
                     return Some(PathResolution::Def(AssocItem::from(assoc).into()));
                 }
                 if let Some(VariantId::EnumVariantId(variant)) =
-                    infer.variant_resolution_for_expr(expr_id)
+                    infer.variant_resolution_for_expr_or_pat(expr_id)
                 {
                     return Some(PathResolution::Def(ModuleDef::Variant(variant.into())));
                 }
@@ -658,7 +660,7 @@ impl SourceAnalyzer {
             } else if let Some(rec_lit) = parent().and_then(ast::RecordExpr::cast) {
                 let expr_id = self.expr_id(db, &rec_lit.into())?;
                 if let Some(VariantId::EnumVariantId(variant)) =
-                    infer.variant_resolution_for_expr(expr_id)
+                    infer.variant_resolution_for_expr_or_pat(expr_id)
                 {
                     return Some(PathResolution::Def(ModuleDef::Variant(variant.into())));
                 }
@@ -790,10 +792,16 @@ impl SourceAnalyzer {
         let infer = self.infer.as_ref()?;
 
         let expr_id = self.expr_id(db, &literal.clone().into())?;
-        let substs = infer.type_of_expr[expr_id].as_adt()?.1;
+        let substs = infer[expr_id].as_adt()?.1;
 
-        let (variant, missing_fields, _exhaustive) =
-            record_literal_missing_fields(db, infer, expr_id, &body[expr_id])?;
+        let (variant, missing_fields, _exhaustive) = match expr_id {
+            ExprOrPatId::ExprId(expr_id) => {
+                record_literal_missing_fields(db, infer, expr_id, &body[expr_id])?
+            }
+            ExprOrPatId::PatId(pat_id) => {
+                record_pattern_missing_fields(db, infer, pat_id, &body[pat_id])?
+            }
+        };
         let res = self.missing_fields(db, substs, variant, missing_fields);
         Some(res)
     }
@@ -856,7 +864,7 @@ impl SourceAnalyzer {
     ) -> Option<VariantId> {
         let infer = self.infer.as_ref()?;
         let expr_id = self.expr_id(db, &record_lit.into())?;
-        infer.variant_resolution_for_expr(expr_id)
+        infer.variant_resolution_for_expr_or_pat(expr_id)
     }
 
     pub(crate) fn is_unsafe_macro_call_expr(
@@ -867,14 +875,24 @@ impl SourceAnalyzer {
         if let (Some((def, body, sm)), Some(infer)) = (&self.def, &self.infer) {
             if let Some(expanded_expr) = sm.macro_expansion_expr(macro_expr) {
                 let mut is_unsafe = false;
-                unsafe_expressions(
-                    db,
-                    infer,
-                    *def,
-                    body,
-                    expanded_expr,
-                    &mut |UnsafeExpr { inside_unsafe_block, .. }| is_unsafe |= !inside_unsafe_block,
-                );
+                let mut walk_expr = |expr_id| {
+                    unsafe_expressions(
+                        db,
+                        infer,
+                        *def,
+                        body,
+                        expr_id,
+                        &mut |UnsafeExpr { inside_unsafe_block, .. }| {
+                            is_unsafe |= !inside_unsafe_block
+                        },
+                    )
+                };
+                match expanded_expr {
+                    ExprOrPatId::ExprId(expanded_expr) => walk_expr(expanded_expr),
+                    ExprOrPatId::PatId(expanded_pat) => {
+                        body.walk_exprs_in_pat(expanded_pat, &mut walk_expr)
+                    }
+                }
                 return is_unsafe;
             }
         }
@@ -991,7 +1009,7 @@ impl SourceAnalyzer {
     }
 
     fn ty_of_expr(&self, db: &dyn HirDatabase, expr: &ast::Expr) -> Option<&Ty> {
-        self.infer.as_ref()?.type_of_expr.get(self.expr_id(db, expr)?)
+        self.infer.as_ref()?.type_of_expr_or_pat(self.expr_id(db, expr)?)
     }
 }
 
@@ -1004,7 +1022,7 @@ fn scope_for(
     node.ancestors_with_macros(db.upcast())
         .take_while(|it| !ast::Item::can_cast(it.kind()) || ast::MacroCall::can_cast(it.kind()))
         .filter_map(|it| it.map(ast::Expr::cast).transpose())
-        .filter_map(|it| source_map.node_expr(it.as_ref()))
+        .filter_map(|it| source_map.node_expr(it.as_ref())?.as_expr())
         .find_map(|it| scopes.scope_for(it))
 }
 
diff --git a/src/tools/rust-analyzer/crates/ide-diagnostics/src/handlers/missing_fields.rs b/src/tools/rust-analyzer/crates/ide-diagnostics/src/handlers/missing_fields.rs
index 86c237f7b5e..3a622c69681 100644
--- a/src/tools/rust-analyzer/crates/ide-diagnostics/src/handlers/missing_fields.rs
+++ b/src/tools/rust-analyzer/crates/ide-diagnostics/src/handlers/missing_fields.rs
@@ -308,22 +308,27 @@ struct T(S);
 fn regular(a: S) {
     let s;
     S { s, .. } = a;
+    _ = s;
 }
 fn nested(a: S2) {
     let s;
     S2 { s: S { s, .. }, .. } = a;
+    _ = s;
 }
 fn in_tuple(a: (S,)) {
     let s;
     (S { s, .. },) = a;
+    _ = s;
 }
 fn in_array(a: [S;1]) {
     let s;
     [S { s, .. },] = a;
+    _ = s;
 }
 fn in_tuple_struct(a: T) {
     let s;
     T(S { s, .. }) = a;
+    _ = s;
 }
             ",
         );
diff --git a/src/tools/rust-analyzer/crates/ide-diagnostics/src/handlers/missing_unsafe.rs b/src/tools/rust-analyzer/crates/ide-diagnostics/src/handlers/missing_unsafe.rs
index cc0f4bfccc9..98063bf4fef 100644
--- a/src/tools/rust-analyzer/crates/ide-diagnostics/src/handlers/missing_unsafe.rs
+++ b/src/tools/rust-analyzer/crates/ide-diagnostics/src/handlers/missing_unsafe.rs
@@ -32,7 +32,8 @@ fn fixes(ctx: &DiagnosticsContext<'_>, d: &hir::MissingUnsafe) -> Option<Vec<Ass
     }
 
     let root = ctx.sema.db.parse_or_expand(d.expr.file_id);
-    let expr = d.expr.value.to_node(&root);
+    let node = d.expr.value.to_node(&root);
+    let expr = node.syntax().ancestors().find_map(ast::Expr::cast)?;
 
     let node_to_add_unsafe_block = pick_best_node_to_add_unsafe_block(&expr)?;
 
diff --git a/src/tools/rust-analyzer/crates/ide-diagnostics/src/handlers/mutability_errors.rs b/src/tools/rust-analyzer/crates/ide-diagnostics/src/handlers/mutability_errors.rs
index dfd58640251..acf1cf1d38d 100644
--- a/src/tools/rust-analyzer/crates/ide-diagnostics/src/handlers/mutability_errors.rs
+++ b/src/tools/rust-analyzer/crates/ide-diagnostics/src/handlers/mutability_errors.rs
@@ -1,5 +1,6 @@
+use hir::db::ExpandDatabase;
 use ide_db::source_change::SourceChange;
-use syntax::{AstNode, SyntaxKind, SyntaxNode, SyntaxToken, T};
+use syntax::{ast, AstNode, SyntaxKind, SyntaxNode, SyntaxNodePtr, SyntaxToken, T};
 use text_edit::TextEdit;
 
 use crate::{fix, Diagnostic, DiagnosticCode, DiagnosticsContext};
@@ -8,14 +9,27 @@ use crate::{fix, Diagnostic, DiagnosticCode, DiagnosticsContext};
 //
 // This diagnostic is triggered on mutating an immutable variable.
 pub(crate) fn need_mut(ctx: &DiagnosticsContext<'_>, d: &hir::NeedMut) -> Option<Diagnostic> {
+    let root = ctx.sema.db.parse_or_expand(d.span.file_id);
+    let node = d.span.value.to_node(&root);
+    let mut span = d.span;
+    if let Some(parent) = node.parent() {
+        if ast::BinExpr::can_cast(parent.kind()) {
+            // In case of an assignment, the diagnostic is provided on the variable name.
+            // We want to expand it to include the whole assignment, but only when this
+            // is an ordinary assignment, not a destructuring assignment. So, the direct
+            // parent is an assignment expression.
+            span = d.span.with_value(SyntaxNodePtr::new(&parent));
+        }
+    };
+
     let fixes = (|| {
         if d.local.is_ref(ctx.sema.db) {
             // There is no simple way to add `mut` to `ref x` and `ref mut x`
             return None;
         }
-        let file_id = d.span.file_id.file_id()?;
+        let file_id = span.file_id.file_id()?;
         let mut edit_builder = TextEdit::builder();
-        let use_range = d.span.value.text_range();
+        let use_range = span.value.text_range();
         for source in d.local.sources(ctx.sema.db) {
             let Some(ast) = source.name() else { continue };
             // FIXME: macros
@@ -29,6 +43,7 @@ pub(crate) fn need_mut(ctx: &DiagnosticsContext<'_>, d: &hir::NeedMut) -> Option
             use_range,
         )])
     })();
+
     Some(
         Diagnostic::new_with_syntax_node_ptr(
             ctx,
@@ -38,7 +53,7 @@ pub(crate) fn need_mut(ctx: &DiagnosticsContext<'_>, d: &hir::NeedMut) -> Option
                 "cannot mutate immutable variable `{}`",
                 d.local.name(ctx.sema.db).display(ctx.sema.db, ctx.edition)
             ),
-            d.span,
+            span,
         )
         .with_fixes(fixes),
     )
@@ -929,7 +944,6 @@ fn fn_once(mut x: impl FnOnce(u8) -> u8) -> u8 {
 
     #[test]
     fn closure() {
-        // FIXME: Diagnostic spans are inconsistent inside and outside closure
         check_diagnostics(
             r#"
         //- minicore: copy, fn
@@ -942,11 +956,11 @@ fn fn_once(mut x: impl FnOnce(u8) -> u8) -> u8 {
         fn f() {
             let x = 5;
             let closure1 = || { x = 2; };
-                              //^ 💡 error: cannot mutate immutable variable `x`
+                              //^^^^^ 💡 error: cannot mutate immutable variable `x`
             let _ = closure1();
                   //^^^^^^^^ 💡 error: cannot mutate immutable variable `closure1`
             let closure2 = || { x = x; };
-                              //^ 💡 error: cannot mutate immutable variable `x`
+                              //^^^^^ 💡 error: cannot mutate immutable variable `x`
             let closure3 = || {
                 let x = 2;
                 x = 5;
@@ -988,7 +1002,7 @@ fn f() {
             || {
                 let x = 2;
                 || { || { x = 5; } }
-                        //^ 💡 error: cannot mutate immutable variable `x`
+                        //^^^^^ 💡 error: cannot mutate immutable variable `x`
             }
         }
     };