4 files changed, 378 insertions, 293 deletions

diff --git a/crates/hir/src/diagnostics.rs b/crates/hir/src/diagnostics.rs
index 2cdbd172a..b4c505898 100644
--- a/crates/hir/src/diagnostics.rs
+++ b/crates/hir/src/diagnostics.rs
@@ -3,251 +3,152 @@
 //!
 //! This probably isn't the best way to do this -- ideally, diagnistics should
 //! be expressed in terms of hir types themselves.
-use std::any::Any;
-
-use cfg::{CfgExpr, CfgOptions, DnfExpr};
+use cfg::{CfgExpr, CfgOptions};
+use either::Either;
 use hir_def::path::ModPath;
-use hir_expand::{HirFileId, InFile};
-use stdx::format_to;
+use hir_expand::{name::Name, HirFileId, InFile};
 use syntax::{ast, AstPtr, SyntaxNodePtr, TextRange};
 
-pub use hir_ty::{
-    diagnostics::{
-        IncorrectCase, MismatchedArgCount, MissingFields, MissingMatchArms,
-        MissingOkOrSomeInTailExpr, NoSuchField, RemoveThisSemicolon,
-        ReplaceFilterMapNextWithFindMap,
-    },
-    diagnostics_sink::{Diagnostic, DiagnosticCode, DiagnosticSink, DiagnosticSinkBuilder},
-};
-
-// Diagnostic: unresolved-module
-//
-// This diagnostic is triggered if rust-analyzer is unable to discover referred module.
+macro_rules! diagnostics {
+    ($($diag:ident,)*) => {
+        pub enum AnyDiagnostic {$(
+            $diag(Box<$diag>),
+        )*}
+
+        $(
+            impl From<$diag> for AnyDiagnostic {
+                fn from(d: $diag) -> AnyDiagnostic {
+                    AnyDiagnostic::$diag(Box::new(d))
+                }
+            }
+        )*
+    };
+}
+
+diagnostics![
+    BreakOutsideOfLoop,
+    InactiveCode,
+    IncorrectCase,
+    MacroError,
+    MismatchedArgCount,
+    MissingFields,
+    MissingMatchArms,
+    MissingOkOrSomeInTailExpr,
+    MissingUnsafe,
+    NoSuchField,
+    RemoveThisSemicolon,
+    ReplaceFilterMapNextWithFindMap,
+    UnimplementedBuiltinMacro,
+    UnresolvedExternCrate,
+    UnresolvedImport,
+    UnresolvedMacroCall,
+    UnresolvedModule,
+    UnresolvedProcMacro,
+];
+
 #[derive(Debug)]
 pub struct UnresolvedModule {
-    pub file: HirFileId,
-    pub decl: AstPtr<ast::Module>,
+    pub decl: InFile<AstPtr<ast::Module>>,
     pub candidate: String,
 }
 
-impl Diagnostic for UnresolvedModule {
-    fn code(&self) -> DiagnosticCode {
-        DiagnosticCode("unresolved-module")
-    }
-    fn message(&self) -> String {
-        "unresolved module".to_string()
-    }
-    fn display_source(&self) -> InFile<SyntaxNodePtr> {
-        InFile::new(self.file, self.decl.clone().into())
-    }
-    fn as_any(&self) -> &(dyn Any + Send + 'static) {
-        self
-    }
-}
-
-// Diagnostic: unresolved-extern-crate
-//
-// This diagnostic is triggered if rust-analyzer is unable to discover referred extern crate.
 #[derive(Debug)]
 pub struct UnresolvedExternCrate {
-    pub file: HirFileId,
-    pub item: AstPtr<ast::ExternCrate>,
-}
-
-impl Diagnostic for UnresolvedExternCrate {
-    fn code(&self) -> DiagnosticCode {
-        DiagnosticCode("unresolved-extern-crate")
-    }
-    fn message(&self) -> String {
-        "unresolved extern crate".to_string()
-    }
-    fn display_source(&self) -> InFile<SyntaxNodePtr> {
-        InFile::new(self.file, self.item.clone().into())
-    }
-    fn as_any(&self) -> &(dyn Any + Send + 'static) {
-        self
-    }
+    pub decl: InFile<AstPtr<ast::ExternCrate>>,
 }
 
 #[derive(Debug)]
 pub struct UnresolvedImport {
-    pub file: HirFileId,
-    pub node: AstPtr<ast::UseTree>,
-}
-
-impl Diagnostic for UnresolvedImport {
-    fn code(&self) -> DiagnosticCode {
-        DiagnosticCode("unresolved-import")
-    }
-    fn message(&self) -> String {
-        "unresolved import".to_string()
-    }
-    fn display_source(&self) -> InFile<SyntaxNodePtr> {
-        InFile::new(self.file, self.node.clone().into())
-    }
-    fn as_any(&self) -> &(dyn Any + Send + 'static) {
-        self
-    }
-    fn is_experimental(&self) -> bool {
-        // This currently results in false positives in the following cases:
-        // - `cfg_if!`-generated code in libstd (we don't load the sysroot correctly)
-        // - `core::arch` (we don't handle `#[path = "../<path>"]` correctly)
-        // - proc macros and/or proc macro generated code
-        true
-    }
-}
-
-// Diagnostic: unresolved-macro-call
-//
-// This diagnostic is triggered if rust-analyzer is unable to resolve the path to a
-// macro in a macro invocation.
+    pub decl: InFile<AstPtr<ast::UseTree>>,
+}
+
 #[derive(Debug, Clone, Eq, PartialEq)]
 pub struct UnresolvedMacroCall {
-    pub file: HirFileId,
-    pub node: AstPtr<ast::MacroCall>,
+    pub macro_call: InFile<AstPtr<ast::MacroCall>>,
     pub path: ModPath,
 }
 
-impl Diagnostic for UnresolvedMacroCall {
-    fn code(&self) -> DiagnosticCode {
-        DiagnosticCode("unresolved-macro-call")
-    }
-    fn message(&self) -> String {
-        format!("unresolved macro `{}!`", self.path)
-    }
-    fn display_source(&self) -> InFile<SyntaxNodePtr> {
-        InFile::new(self.file, self.node.clone().into())
-    }
-    fn as_any(&self) -> &(dyn Any + Send + 'static) {
-        self
-    }
-    fn is_experimental(&self) -> bool {
-        true
-    }
-}
-
-// Diagnostic: inactive-code
-//
-// This diagnostic is shown for code with inactive `#[cfg]` attributes.
 #[derive(Debug, Clone, Eq, PartialEq)]
 pub struct InactiveCode {
-    pub file: HirFileId,
-    pub node: SyntaxNodePtr,
+    pub node: InFile<SyntaxNodePtr>,
     pub cfg: CfgExpr,
     pub opts: CfgOptions,
 }
 
-impl Diagnostic for InactiveCode {
-    fn code(&self) -> DiagnosticCode {
-        DiagnosticCode("inactive-code")
-    }
-    fn message(&self) -> String {
-        let inactive = DnfExpr::new(self.cfg.clone()).why_inactive(&self.opts);
-        let mut buf = "code is inactive due to #[cfg] directives".to_string();
-
-        if let Some(inactive) = inactive {
-            format_to!(buf, ": {}", inactive);
-        }
-
-        buf
-    }
-    fn display_source(&self) -> InFile<SyntaxNodePtr> {
-        InFile::new(self.file, self.node.clone())
-    }
-    fn as_any(&self) -> &(dyn Any + Send + 'static) {
-        self
-    }
-}
-
-// Diagnostic: unresolved-proc-macro
-//
-// This diagnostic is shown when a procedural macro can not be found. This usually means that
-// procedural macro support is simply disabled (and hence is only a weak hint instead of an error),
-// but can also indicate project setup problems.
-//
-// If you are seeing a lot of "proc macro not expanded" warnings, you can add this option to the
-// `rust-analyzer.diagnostics.disabled` list to prevent them from showing. Alternatively you can
-// enable support for procedural macros (see `rust-analyzer.procMacro.enable`).
 #[derive(Debug, Clone, Eq, PartialEq)]
 pub struct UnresolvedProcMacro {
-    pub file: HirFileId,
-    pub node: SyntaxNodePtr,
+    pub node: InFile<SyntaxNodePtr>,
     /// If the diagnostic can be pinpointed more accurately than via `node`, this is the `TextRange`
     /// to use instead.
     pub precise_location: Option<TextRange>,
     pub macro_name: Option<String>,
 }
 
-impl Diagnostic for UnresolvedProcMacro {
-    fn code(&self) -> DiagnosticCode {
-        DiagnosticCode("unresolved-proc-macro")
-    }
+#[derive(Debug, Clone, Eq, PartialEq)]
+pub struct MacroError {
+    pub node: InFile<SyntaxNodePtr>,
+    pub message: String,
+}
 
-    fn message(&self) -> String {
-        match &self.macro_name {
-            Some(name) => format!("proc macro `{}` not expanded", name),
-            None => "proc macro not expanded".to_string(),
-        }
-    }
+#[derive(Debug)]
+pub struct UnimplementedBuiltinMacro {
+    pub node: InFile<SyntaxNodePtr>,
+}
 
-    fn display_source(&self) -> InFile<SyntaxNodePtr> {
-        InFile::new(self.file, self.node.clone())
-    }
+#[derive(Debug)]
+pub struct NoSuchField {
+    pub field: InFile<AstPtr<ast::RecordExprField>>,
+}
 
-    fn as_any(&self) -> &(dyn Any + Send + 'static) {
-        self
-    }
+#[derive(Debug)]
+pub struct BreakOutsideOfLoop {
+    pub expr: InFile<AstPtr<ast::Expr>>,
 }
 
-// Diagnostic: macro-error
-//
-// This diagnostic is shown for macro expansion errors.
-#[derive(Debug, Clone, Eq, PartialEq)]
-pub struct MacroError {
-    pub file: HirFileId,
-    pub node: SyntaxNodePtr,
-    pub message: String,
+#[derive(Debug)]
+pub struct MissingUnsafe {
+    pub expr: InFile<AstPtr<ast::Expr>>,
 }
 
-impl Diagnostic for MacroError {
-    fn code(&self) -> DiagnosticCode {
-        DiagnosticCode("macro-error")
-    }
-    fn message(&self) -> String {
-        self.message.clone()
-    }
-    fn display_source(&self) -> InFile<SyntaxNodePtr> {
-        InFile::new(self.file, self.node.clone())
-    }
-    fn as_any(&self) -> &(dyn Any + Send + 'static) {
-        self
-    }
-    fn is_experimental(&self) -> bool {
-        // Newly added and not very well-tested, might contain false positives.
-        true
-    }
+#[derive(Debug)]
+pub struct MissingFields {
+    pub file: HirFileId,
+    pub field_list_parent: Either<AstPtr<ast::RecordExpr>, AstPtr<ast::RecordPat>>,
+    pub field_list_parent_path: Option<AstPtr<ast::Path>>,
+    pub missed_fields: Vec<Name>,
 }
 
 #[derive(Debug)]
-pub struct UnimplementedBuiltinMacro {
+pub struct ReplaceFilterMapNextWithFindMap {
     pub file: HirFileId,
-    pub node: SyntaxNodePtr,
+    /// This expression is the whole method chain up to and including `.filter_map(..).next()`.
+    pub next_expr: AstPtr<ast::Expr>,
 }
 
-impl Diagnostic for UnimplementedBuiltinMacro {
-    fn code(&self) -> DiagnosticCode {
-        DiagnosticCode("unimplemented-builtin-macro")
-    }
+#[derive(Debug)]
+pub struct MismatchedArgCount {
+    pub call_expr: InFile<AstPtr<ast::Expr>>,
+    pub expected: usize,
+    pub found: usize,
+}
 
-    fn message(&self) -> String {
-        "unimplemented built-in macro".to_string()
-    }
+#[derive(Debug)]
+pub struct RemoveThisSemicolon {
+    pub expr: InFile<AstPtr<ast::Expr>>,
+}
 
-    fn display_source(&self) -> InFile<SyntaxNodePtr> {
-        InFile::new(self.file, self.node.clone())
-    }
+#[derive(Debug)]
+pub struct MissingOkOrSomeInTailExpr {
+    pub expr: InFile<AstPtr<ast::Expr>>,
+    // `Some` or `Ok` depending on whether the return type is Result or Option
+    pub required: String,
+}
 
-    fn as_any(&self) -> &(dyn Any + Send + 'static) {
-        self
-    }
+#[derive(Debug)]
+pub struct MissingMatchArms {
+    pub file: HirFileId,
+    pub match_expr: AstPtr<ast::Expr>,
+    pub arms: AstPtr<ast::MatchArmList>,
 }
+
+pub use hir_ty::diagnostics::IncorrectCase;
diff --git a/crates/hir/src/lib.rs b/crates/hir/src/lib.rs
index 2ec568b26..5bc0b2338 100644
--- a/crates/hir/src/lib.rs
+++ b/crates/hir/src/lib.rs
@@ -35,14 +35,10 @@ use std::{iter, sync::Arc};
 
 use arrayvec::ArrayVec;
 use base_db::{CrateDisplayName, CrateId, Edition, FileId};
-use diagnostics::{
-    InactiveCode, MacroError, UnimplementedBuiltinMacro, UnresolvedExternCrate, UnresolvedImport,
-    UnresolvedMacroCall, UnresolvedModule, UnresolvedProcMacro,
-};
 use either::Either;
 use hir_def::{
     adt::{ReprKind, VariantData},
-    body::BodyDiagnostic,
+    body::{BodyDiagnostic, SyntheticSyntax},
     expr::{BindingAnnotation, LabelId, Pat, PatId},
     item_tree::ItemTreeNode,
     lang_item::LangItemTarget,
@@ -60,8 +56,8 @@ use hir_ty::{
     autoderef,
     consteval::ConstExt,
     could_unify,
-    diagnostics_sink::DiagnosticSink,
-    method_resolution::{self, def_crates, TyFingerprint},
+    diagnostics::BodyValidationDiagnostic,
+    method_resolution::{self, TyFingerprint},
     primitive::UintTy,
     subst_prefix,
     traits::FnTrait,
@@ -72,6 +68,7 @@ use hir_ty::{
 };
 use itertools::Itertools;
 use nameres::diagnostics::DefDiagnosticKind;
+use once_cell::unsync::Lazy;
 use rustc_hash::FxHashSet;
 use stdx::{format_to, impl_from};
 use syntax::{
@@ -84,6 +81,13 @@ use crate::db::{DefDatabase, HirDatabase};
 
 pub use crate::{
     attrs::{HasAttrs, Namespace},
+    diagnostics::{
+        AnyDiagnostic, BreakOutsideOfLoop, InactiveCode, IncorrectCase, MacroError,
+        MismatchedArgCount, MissingFields, MissingMatchArms, MissingOkOrSomeInTailExpr,
+        MissingUnsafe, NoSuchField, RemoveThisSemicolon, ReplaceFilterMapNextWithFindMap,
+        UnimplementedBuiltinMacro, UnresolvedExternCrate, UnresolvedImport, UnresolvedMacroCall,
+        UnresolvedModule, UnresolvedProcMacro,
+    },
     has_source::HasSource,
     semantics::{PathResolution, Semantics, SemanticsScope},
 };
@@ -191,6 +195,7 @@ impl Crate {
         db: &dyn DefDatabase,
         query: import_map::Query,
     ) -> impl Iterator<Item = Either<ModuleDef, MacroDef>> {
+        let _p = profile::span("query_external_importables");
         import_map::search_dependencies(db, self.into(), query).into_iter().map(|item| match item {
             ItemInNs::Types(mod_id) | ItemInNs::Values(mod_id) => Either::Left(mod_id.into()),
             ItemInNs::Macros(mac_id) => Either::Right(mac_id.into()),
@@ -331,7 +336,7 @@ impl ModuleDef {
         }
     }
 
-    pub fn diagnostics(self, db: &dyn HirDatabase, sink: &mut DiagnosticSink) {
+    pub fn diagnostics(self, db: &dyn HirDatabase) -> Vec<AnyDiagnostic> {
         let id = match self {
             ModuleDef::Adt(it) => match it {
                 Adt::Struct(it) => it.id.into(),
@@ -344,15 +349,19 @@ impl ModuleDef {
             ModuleDef::Module(it) => it.id.into(),
             ModuleDef::Const(it) => it.id.into(),
             ModuleDef::Static(it) => it.id.into(),
-            _ => return,
+            _ => return Vec::new(),
         };
 
         let module = match self.module(db) {
             Some(it) => it,
-            None => return,
+            None => return Vec::new(),
         };
 
-        hir_ty::diagnostics::validate_module_item(db, module.id.krate(), id, sink)
+        let mut acc = Vec::new();
+        for diag in hir_ty::diagnostics::validate_module_item(db, module.id.krate(), id) {
+            acc.push(diag.into())
+        }
+        acc
     }
 }
 
@@ -441,10 +450,10 @@ impl Module {
     }
 
     pub fn visibility_of(self, db: &dyn HirDatabase, def: &ModuleDef) -> Option<Visibility> {
-        self.id.def_map(db.upcast())[self.id.local_id].scope.visibility_of(def.clone().into())
+        self.id.def_map(db.upcast())[self.id.local_id].scope.visibility_of((*def).into())
     }
 
-    pub fn diagnostics(self, db: &dyn HirDatabase, sink: &mut DiagnosticSink) {
+    pub fn diagnostics(self, db: &dyn HirDatabase, acc: &mut Vec<AnyDiagnostic>) {
         let _p = profile::span("Module::diagnostics").detail(|| {
             format!("{:?}", self.name(db).map_or("<unknown>".into(), |name| name.to_string()))
         });
@@ -457,18 +466,22 @@ impl Module {
             match &diag.kind {
                 DefDiagnosticKind::UnresolvedModule { ast: declaration, candidate } => {
                     let decl = declaration.to_node(db.upcast());
-                    sink.push(UnresolvedModule {
-                        file: declaration.file_id,
-                        decl: AstPtr::new(&decl),
-                        candidate: candidate.clone(),
-                    })
+                    acc.push(
+                        UnresolvedModule {
+                            decl: InFile::new(declaration.file_id, AstPtr::new(&decl)),
+                            candidate: candidate.clone(),
+                        }
+                        .into(),
+                    )
                 }
                 DefDiagnosticKind::UnresolvedExternCrate { ast } => {
                     let item = ast.to_node(db.upcast());
-                    sink.push(UnresolvedExternCrate {
-                        file: ast.file_id,
-                        item: AstPtr::new(&item),
-                    });
+                    acc.push(
+                        UnresolvedExternCrate {
+                            decl: InFile::new(ast.file_id, AstPtr::new(&item)),
+                        }
+                        .into(),
+                    );
                 }
 
                 DefDiagnosticKind::UnresolvedImport { id, index } => {
@@ -477,25 +490,30 @@ impl Module {
                     let import = &item_tree[id.value];
 
                     let use_tree = import.use_tree_to_ast(db.upcast(), file_id, *index);
-                    sink.push(UnresolvedImport { file: file_id, node: AstPtr::new(&use_tree) });
+                    acc.push(
+                        UnresolvedImport { decl: InFile::new(file_id, AstPtr::new(&use_tree)) }
+                            .into(),
+                    );
                 }
 
                 DefDiagnosticKind::UnconfiguredCode { ast, cfg, opts } => {
                     let item = ast.to_node(db.upcast());
-                    sink.push(InactiveCode {
-                        file: ast.file_id,
-                        node: AstPtr::new(&item).into(),
-                        cfg: cfg.clone(),
-                        opts: opts.clone(),
-                    });
+                    acc.push(
+                        InactiveCode {
+                            node: ast.with_value(AstPtr::new(&item).into()),
+                            cfg: cfg.clone(),
+                            opts: opts.clone(),
+                        }
+                        .into(),
+                    );
                 }
 
                 DefDiagnosticKind::UnresolvedProcMacro { ast } => {
                     let mut precise_location = None;
-                    let (file, ast, name) = match ast {
+                    let (node, name) = match ast {
                         MacroCallKind::FnLike { ast_id, .. } => {
                             let node = ast_id.to_node(db.upcast());
-                            (ast_id.file_id, SyntaxNodePtr::from(AstPtr::new(&node)), None)
+                            (ast_id.with_value(SyntaxNodePtr::from(AstPtr::new(&node))), None)
                         }
                         MacroCallKind::Derive { ast_id, derive_name, .. } => {
                             let node = ast_id.to_node(db.upcast());
@@ -528,8 +546,7 @@ impl Module {
                             }
 
                             (
-                                ast_id.file_id,
-                                SyntaxNodePtr::from(AstPtr::new(&node)),
+                                ast_id.with_value(SyntaxNodePtr::from(AstPtr::new(&node))),
                                 Some(derive_name.clone()),
                             )
                         }
@@ -540,73 +557,73 @@ impl Module {
                                     || panic!("cannot find attribute #{}", invoc_attr_index),
                                 );
                             (
-                                ast_id.file_id,
-                                SyntaxNodePtr::from(AstPtr::new(&attr)),
+                                ast_id.with_value(SyntaxNodePtr::from(AstPtr::new(&attr))),
                                 Some(attr_name.clone()),
                             )
                         }
                     };
-                    sink.push(UnresolvedProcMacro {
-                        file,
-                        node: ast,
-                        precise_location,
-                        macro_name: name,
-                    });
+                    acc.push(
+                        UnresolvedProcMacro { node, precise_location, macro_name: name }.into(),
+                    );
                 }
 
                 DefDiagnosticKind::UnresolvedMacroCall { ast, path } => {
                     let node = ast.to_node(db.upcast());
-                    sink.push(UnresolvedMacroCall {
-                        file: ast.file_id,
-                        node: AstPtr::new(&node),
-                        path: path.clone(),
-                    });
+                    acc.push(
+                        UnresolvedMacroCall {
+                            macro_call: InFile::new(ast.file_id, AstPtr::new(&node)),
+                            path: path.clone(),
+                        }
+                        .into(),
+                    );
                 }
 
                 DefDiagnosticKind::MacroError { ast, message } => {
-                    let (file, ast) = match ast {
+                    let node = match ast {
                         MacroCallKind::FnLike { ast_id, .. } => {
                             let node = ast_id.to_node(db.upcast());
-                            (ast_id.file_id, SyntaxNodePtr::from(AstPtr::new(&node)))
+                            ast_id.with_value(SyntaxNodePtr::from(AstPtr::new(&node)))
                         }
                         MacroCallKind::Derive { ast_id, .. }
                         | MacroCallKind::Attr { ast_id, .. } => {
                             // FIXME: point to the attribute instead, this creates very large diagnostics
                             let node = ast_id.to_node(db.upcast());
-                            (ast_id.file_id, SyntaxNodePtr::from(AstPtr::new(&node)))
+                            ast_id.with_value(SyntaxNodePtr::from(AstPtr::new(&node)))
                         }
                     };
-                    sink.push(MacroError { file, node: ast, message: message.clone() });
+                    acc.push(MacroError { node, message: message.clone() }.into());
                 }
 
                 DefDiagnosticKind::UnimplementedBuiltinMacro { ast } => {
                     let node = ast.to_node(db.upcast());
                     // Must have a name, otherwise we wouldn't emit it.
                     let name = node.name().expect("unimplemented builtin macro with no name");
-                    let ptr = SyntaxNodePtr::from(AstPtr::new(&name));
-                    sink.push(UnimplementedBuiltinMacro { file: ast.file_id, node: ptr });
+                    acc.push(
+                        UnimplementedBuiltinMacro {
+                            node: ast.with_value(SyntaxNodePtr::from(AstPtr::new(&name))),
+                        }
+                        .into(),
+                    );
                 }
             }
         }
         for decl in self.declarations(db) {
             match decl {
-                crate::ModuleDef::Function(f) => f.diagnostics(db, sink),
-                crate::ModuleDef::Module(m) => {
+                ModuleDef::Function(f) => f.diagnostics(db, acc),
+                ModuleDef::Module(m) => {
                     // Only add diagnostics from inline modules
                     if def_map[m.id.local_id].origin.is_inline() {
-                        m.diagnostics(db, sink)
+                        m.diagnostics(db, acc)
                     }
                 }
-                _ => {
-                    decl.diagnostics(db, sink);
-                }
+                _ => acc.extend(decl.diagnostics(db)),
             }
         }
 
         for impl_def in self.impl_defs(db) {
             for item in impl_def.items(db) {
                 if let AssocItem::Function(f) = item {
-                    f.diagnostics(db, sink);
+                    f.diagnostics(db, acc);
                 }
             }
         }
@@ -1008,41 +1025,191 @@ impl Function {
         db.function_data(self.id).is_async()
     }
 
-    pub fn diagnostics(self, db: &dyn HirDatabase, sink: &mut DiagnosticSink) {
+    pub fn diagnostics(self, db: &dyn HirDatabase, acc: &mut Vec<AnyDiagnostic>) {
         let krate = self.module(db).id.krate();
 
         let source_map = db.body_with_source_map(self.id.into()).1;
         for diag in source_map.diagnostics() {
             match diag {
-                BodyDiagnostic::InactiveCode { node, cfg, opts } => sink.push(InactiveCode {
-                    file: node.file_id,
-                    node: node.value.clone(),
-                    cfg: cfg.clone(),
-                    opts: opts.clone(),
-                }),
-                BodyDiagnostic::MacroError { node, message } => sink.push(MacroError {
-                    file: node.file_id,
-                    node: node.value.clone().into(),
-                    message: message.to_string(),
-                }),
-                BodyDiagnostic::UnresolvedProcMacro { node } => sink.push(UnresolvedProcMacro {
-                    file: node.file_id,
-                    node: node.value.clone().into(),
-                    precise_location: None,
-                    macro_name: None,
-                }),
-                BodyDiagnostic::UnresolvedMacroCall { node, path } => {
-                    sink.push(UnresolvedMacroCall {
-                        file: node.file_id,
-                        node: node.value.clone(),
-                        path: path.clone(),
-                    })
+                BodyDiagnostic::InactiveCode { node, cfg, opts } => acc.push(
+                    InactiveCode { node: node.clone(), cfg: cfg.clone(), opts: opts.clone() }
+                        .into(),
+                ),
+                BodyDiagnostic::MacroError { node, message } => acc.push(
+                    MacroError {
+                        node: node.clone().map(|it| it.into()),
+                        message: message.to_string(),
+                    }
+                    .into(),
+                ),
+                BodyDiagnostic::UnresolvedProcMacro { node } => acc.push(
+                    UnresolvedProcMacro {
+                        node: node.clone().map(|it| it.into()),
+                        precise_location: None,
+                        macro_name: None,
+                    }
+                    .into(),
+                ),
+                BodyDiagnostic::UnresolvedMacroCall { node, path } => acc.push(
+                    UnresolvedMacroCall { macro_call: node.clone(), path: path.clone() }.into(),
+                ),
+            }
+        }
+
+        let infer = db.infer(self.id.into());
+        let source_map = Lazy::new(|| db.body_with_source_map(self.id.into()).1);
+        for d in &infer.diagnostics {
+            match d {
+                hir_ty::InferenceDiagnostic::NoSuchField { expr } => {
+                    let field = source_map.field_syntax(*expr);
+                    acc.push(NoSuchField { field }.into())
+                }
+                hir_ty::InferenceDiagnostic::BreakOutsideOfLoop { expr } => {
+                    let expr = source_map
+                        .expr_syntax(*expr)
+                        .expect("break outside of loop in synthetic syntax");
+                    acc.push(BreakOutsideOfLoop { expr }.into())
+                }
+            }
+        }
+
+        for expr in hir_ty::diagnostics::missing_unsafe(db, self.id.into()) {
+            match source_map.expr_syntax(expr) {
+                Ok(expr) => acc.push(MissingUnsafe { expr }.into()),
+                Err(SyntheticSyntax) => {
+                    // FIXME: Here and eslwhere in this file, the `expr` was
+                    // desugared, report or assert that this doesn't happen.
+                }
+            }
+        }
+
+        for diagnostic in BodyValidationDiagnostic::collect(db, self.id.into()) {
+            match diagnostic {
+                BodyValidationDiagnostic::RecordMissingFields {
+                    record,
+                    variant,
+                    missed_fields,
+                } => {
+                    let variant_data = variant.variant_data(db.upcast());
+                    let missed_fields = missed_fields
+                        .into_iter()
+                        .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 let Some(_) = record_expr.record_expr_field_list() {
+                                        acc.push(
+                                            MissingFields {
+                                                file: source_ptr.file_id,
+                                                field_list_parent: Either::Left(AstPtr::new(
+                                                    record_expr,
+                                                )),
+                                                field_list_parent_path: record_expr
+                                                    .path()
+                                                    .map(|path| AstPtr::new(&path)),
+                                                missed_fields,
+                                            }
+                                            .into(),
+                                        )
+                                    }
+                                }
+                            }
+                            Err(SyntheticSyntax) => (),
+                        },
+                        Either::Right(record_pat) => match source_map.pat_syntax(record_pat) {
+                            Ok(source_ptr) => {
+                                if let Some(expr) = source_ptr.value.as_ref().left() {
+                                    let root = source_ptr.file_syntax(db.upcast());
+                                    if let ast::Pat::RecordPat(record_pat) = expr.to_node(&root) {
+                                        if let Some(_) = record_pat.record_pat_field_list() {
+                                            acc.push(
+                                                MissingFields {
+                                                    file: source_ptr.file_id,
+                                                    field_list_parent: Either::Right(AstPtr::new(
+                                                        &record_pat,
+                                                    )),
+                                                    field_list_parent_path: record_pat
+                                                        .path()
+                                                        .map(|path| AstPtr::new(&path)),
+                                                    missed_fields,
+                                                }
+                                                .into(),
+                                            )
+                                        }
+                                    }
+                                }
+                            }
+                            Err(SyntheticSyntax) => (),
+                        },
+                    }
+                }
+                BodyValidationDiagnostic::ReplaceFilterMapNextWithFindMap { method_call_expr } => {
+                    if let Ok(next_source_ptr) = source_map.expr_syntax(method_call_expr) {
+                        acc.push(
+                            ReplaceFilterMapNextWithFindMap {
+                                file: next_source_ptr.file_id,
+                                next_expr: next_source_ptr.value,
+                            }
+                            .into(),
+                        );
+                    }
+                }
+                BodyValidationDiagnostic::MismatchedArgCount { call_expr, expected, found } => {
+                    match source_map.expr_syntax(call_expr) {
+                        Ok(source_ptr) => acc.push(
+                            MismatchedArgCount { call_expr: source_ptr, expected, found }.into(),
+                        ),
+                        Err(SyntheticSyntax) => (),
+                    }
+                }
+                BodyValidationDiagnostic::RemoveThisSemicolon { expr } => {
+                    match source_map.expr_syntax(expr) {
+                        Ok(expr) => acc.push(RemoveThisSemicolon { expr }.into()),
+                        Err(SyntheticSyntax) => (),
+                    }
+                }
+                BodyValidationDiagnostic::MissingOkOrSomeInTailExpr { expr, required } => {
+                    match source_map.expr_syntax(expr) {
+                        Ok(expr) => acc.push(MissingOkOrSomeInTailExpr { expr, required }.into()),
+                        Err(SyntheticSyntax) => (),
+                    }
+                }
+                BodyValidationDiagnostic::MissingMatchArms { match_expr } => {
+                    match source_map.expr_syntax(match_expr) {
+                        Ok(source_ptr) => {
+                            let root = source_ptr.file_syntax(db.upcast());
+                            if let ast::Expr::MatchExpr(match_expr) =
+                                &source_ptr.value.to_node(&root)
+                            {
+                                if let (Some(match_expr), Some(arms)) =
+                                    (match_expr.expr(), match_expr.match_arm_list())
+                                {
+                                    acc.push(
+                                        MissingMatchArms {
+                                            file: source_ptr.file_id,
+                                            match_expr: AstPtr::new(&match_expr),
+                                            arms: AstPtr::new(&arms),
+                                        }
+                                        .into(),
+                                    )
+                                }
+                            }
+                        }
+                        Err(SyntheticSyntax) => (),
+                    }
                 }
             }
         }
 
-        hir_ty::diagnostics::validate_module_item(db, krate, self.id.into(), sink);
-        hir_ty::diagnostics::validate_body(db, self.id.into(), sink);
+        for diag in hir_ty::diagnostics::validate_module_item(db, krate, self.id.into()) {
+            acc.push(diag.into())
+        }
     }
 
     /// Whether this function declaration has a definition.
@@ -1450,6 +1617,20 @@ impl AssocItem {
             _ => None,
         }
     }
+
+    pub fn containing_trait_impl(self, db: &dyn HirDatabase) -> Option<Trait> {
+        match self.container(db) {
+            AssocItemContainer::Impl(i) => i.trait_(db),
+            _ => None,
+        }
+    }
+
+    pub fn containing_trait_or_trait_impl(self, db: &dyn HirDatabase) -> Option<Trait> {
+        match self.container(db) {
+            AssocItemContainer::Trait(t) => Some(t),
+            AssocItemContainer::Impl(i) => i.trait_(db),
+        }
+    }
 }
 
 impl HasVisibility for AssocItem {
@@ -1747,7 +1928,7 @@ impl Impl {
     }
 
     pub fn all_for_type(db: &dyn HirDatabase, Type { krate, ty, .. }: Type) -> Vec<Impl> {
-        let def_crates = match def_crates(db, &ty, krate) {
+        let def_crates = match method_resolution::def_crates(db, &ty, krate) {
             Some(def_crates) => def_crates,
             None => return Vec::new(),
         };
@@ -2153,7 +2334,7 @@ impl Type {
         krate: Crate,
         mut callback: impl FnMut(AssocItem) -> Option<T>,
     ) -> Option<T> {
-        for krate in def_crates(db, &self.ty, krate.id)? {
+        for krate in method_resolution::def_crates(db, &self.ty, krate.id)? {
             let impls = db.inherent_impls_in_crate(krate);
 
             for impl_def in impls.for_self_ty(&self.ty) {
@@ -2185,6 +2366,7 @@ impl Type {
         name: Option<&Name>,
         mut callback: impl FnMut(&Ty, Function) -> Option<T>,
     ) -> Option<T> {
+        let _p = profile::span("iterate_method_candidates");
         // There should be no inference vars in types passed here
         // FIXME check that?
         // FIXME replace Unknown by bound vars here
@@ -2218,6 +2400,7 @@ impl Type {
         name: Option<&Name>,
         mut callback: impl FnMut(&Ty, AssocItem) -> Option<T>,
     ) -> Option<T> {
+        let _p = profile::span("iterate_path_candidates");
         let canonical = hir_ty::replace_errors_with_variables(&self.ty);
 
         let env = self.env.clone();
@@ -2255,6 +2438,7 @@ impl Type {
         &'a self,
         db: &'a dyn HirDatabase,
     ) -> impl Iterator<Item = Trait> + 'a {
+        let _p = profile::span("applicable_inherent_traits");
         self.autoderef(db)
             .filter_map(|derefed_type| derefed_type.ty.dyn_trait())
             .flat_map(move |dyn_trait_id| hir_ty::all_super_traits(db.upcast(), dyn_trait_id))
@@ -2327,13 +2511,13 @@ impl Type {
             match ty.kind(&Interner) {
                 TyKind::Adt(_, substs) => {
                     cb(type_.derived(ty.clone()));
-                    walk_substs(db, type_, &substs, cb);
+                    walk_substs(db, type_, substs, cb);
                 }
                 TyKind::AssociatedType(_, substs) => {
                     if let Some(_) = ty.associated_type_parent_trait(db) {
                         cb(type_.derived(ty.clone()));
                     }
-                    walk_substs(db, type_, &substs, cb);
+                    walk_substs(db, type_, substs, cb);
                 }
                 TyKind::OpaqueType(_, subst) => {
                     if let Some(bounds) = ty.impl_trait_bounds(db) {
@@ -2373,7 +2557,7 @@ impl Type {
                 TyKind::FnDef(_, substs)
                 | TyKind::Tuple(_, substs)
                 | TyKind::Closure(.., substs) => {
-                    walk_substs(db, type_, &substs, cb);
+                    walk_substs(db, type_, substs, cb);
                 }
                 TyKind::Function(hir_ty::FnPointer { substitution, .. }) => {
                     walk_substs(db, type_, &substitution.0, cb);
diff --git a/crates/hir/src/semantics.rs b/crates/hir/src/semantics.rs
index d522d5245..613266e07 100644
--- a/crates/hir/src/semantics.rs
+++ b/crates/hir/src/semantics.rs
@@ -192,7 +192,7 @@ impl<'db, DB: HirDatabase> Semantics<'db, DB> {
         node: &SyntaxNode,
         offset: TextSize,
     ) -> Option<N> {
-        if let Some(it) = find_node_at_offset(&node, offset) {
+        if let Some(it) = find_node_at_offset(node, offset) {
             return Some(it);
         }
 
@@ -744,7 +744,7 @@ impl<'db> SemanticsImpl<'db> {
                     return None;
                 }
 
-                let func = self.resolve_method_call(&method_call_expr).map(Function::from)?;
+                let func = self.resolve_method_call(method_call_expr).map(Function::from)?;
                 let res = match func.self_param(self.db)?.access(self.db) {
                     Access::Shared | Access::Exclusive => true,
                     Access::Owned => false,
diff --git a/crates/hir/src/source_analyzer.rs b/crates/hir/src/source_analyzer.rs
index 37a050415..c9744d81d 100644
--- a/crates/hir/src/source_analyzer.rs
+++ b/crates/hir/src/source_analyzer.rs
@@ -222,7 +222,7 @@ impl SourceAnalyzer {
             Pat::Path(path) => path,
             _ => return None,
         };
-        let res = resolve_hir_path(db, &self.resolver, &path)?;
+        let res = resolve_hir_path(db, &self.resolver, path)?;
         match res {
             PathResolution::Def(def) => Some(def),
             _ => None,
@@ -329,7 +329,7 @@ impl SourceAnalyzer {
 
         let (variant, missing_fields, _exhaustive) =
             record_literal_missing_fields(db, infer, expr_id, &body[expr_id])?;
-        let res = self.missing_fields(db, krate, &substs, variant, missing_fields);
+        let res = self.missing_fields(db, krate, substs, variant, missing_fields);
         Some(res)
     }
 
@@ -347,7 +347,7 @@ impl SourceAnalyzer {
 
         let (variant, missing_fields, _exhaustive) =
             record_pattern_missing_fields(db, infer, pat_id, &body[pat_id])?;
-        let res = self.missing_fields(db, krate, &substs, variant, missing_fields);
+        let res = self.missing_fields(db, krate, substs, variant, missing_fields);
         Some(res)
     }