126 files changed, 1851 insertions, 1229 deletions
diff --git a/crates/expect/src/lib.rs b/crates/expect/src/lib.rs
index 21a458d47..bd83895f7 100644
--- a/crates/expect/src/lib.rs
+++ b/crates/expect/src/lib.rs
@@ -74,7 +74,7 @@ impl fmt::Display for Position {
 impl Expect {
    pub fn assert_eq(&self, actual: &str) {
        let trimmed = self.trimmed();
-        if &trimmed == actual {
+        if trimmed == actual {
            return;
        }
        Runtime::fail_expect(self, &trimmed, actual);
diff --git a/crates/flycheck/src/lib.rs b/crates/flycheck/src/lib.rs
index 7c38f5ef9..31e14246d 100644
--- a/crates/flycheck/src/lib.rs
+++ b/crates/flycheck/src/lib.rs
@@ -1,4 +1,4 @@
-//! cargo_check provides the functionality needed to run `cargo check` or
+//! Flycheck provides the functionality needed to run `cargo check` or
 //! another compatible command (f.x. clippy) in a background thread and provide
 //! LSP diagnostics based on the output of the command.
@@ -147,6 +147,12 @@ impl FlycheckActor {
                    // avoid busy-waiting.
                    let cargo_handle = self.cargo_handle.take().unwrap();
                    let res = cargo_handle.join();
+                    if res.is_err() {
+                        log::error!(
+                            "Flycheck failed to run the following command: {:?}",
+                            self.check_command()
+                        )
+                    }
                    self.send(Message::Progress(Progress::DidFinish(res)));
                }
                Event::CheckEvent(Some(message)) => match message {
@@ -253,7 +259,7 @@ impl CargoHandle {
            return Err(io::Error::new(
                io::ErrorKind::Other,
                format!(
-                    "Cargo watcher failed,the command produced no valid metadata (exit code: {:?})",
+                    "Cargo watcher failed, the command produced no valid metadata (exit code: {:?})",
                    exit_status
                ),
            ));
diff --git a/crates/ra_assists/src/ast_transform.rs b/crates/ra_assists/src/ast_transform.rs
index 15ec75c95..07c978378 100644
--- a/crates/ra_assists/src/ast_transform.rs
+++ b/crates/ra_assists/src/ast_transform.rs
@@ -51,7 +51,7 @@ impl<'a> SubstituteTypeParams<'a> {
            // this is a trait impl, so we need to skip the first type parameter -- this is a bit hacky
            .skip(1)
            // The actual list of trait type parameters may be longer than the one
-            // used in the `impl` block due to trailing default type parametrs.
+            // used in the `impl` block due to trailing default type parameters.
            // For that case we extend the `substs` with an empty iterator so we
            // can still hit those trailing values and check if they actually have
            // a default type. If they do, go for that type from `hir` to `ast` so
diff --git a/crates/ra_assists/src/handlers/add_custom_impl.rs b/crates/ra_assists/src/handlers/add_custom_impl.rs
index b67438b6b..ebdf00e67 100644
--- a/crates/ra_assists/src/handlers/add_custom_impl.rs
+++ b/crates/ra_assists/src/handlers/add_custom_impl.rs
@@ -1,10 +1,10 @@
+use itertools::Itertools;
 use ra_syntax::{
    ast::{self, AstNode},
    Direction, SmolStr,
    SyntaxKind::{IDENT, WHITESPACE},
    TextRange, TextSize,
 };
-use stdx::SepBy;
 use crate::{
    assist_context::{AssistContext, Assists},
@@ -61,9 +61,9 @@ pub(crate) fn add_custom_impl(acc: &mut Assists, ctx: &AssistContext) -> Option<
            .filter(|t| t != trait_token.text())
            .collect::<Vec<SmolStr>>();
        let has_more_derives = !new_attr_input.is_empty();
-        let new_attr_input = new_attr_input.iter().sep_by(", ").surround_with("(", ")").to_string();
        if has_more_derives {
+            let new_attr_input = format!("({})", new_attr_input.iter().format(", "));
            builder.replace(input.syntax().text_range(), new_attr_input);
        } else {
            let attr_range = attr.syntax().text_range();
diff --git a/crates/ra_assists/src/handlers/add_turbo_fish.rs b/crates/ra_assists/src/handlers/add_turbo_fish.rs
index 0c565e89a..537322a72 100644
--- a/crates/ra_assists/src/handlers/add_turbo_fish.rs
+++ b/crates/ra_assists/src/handlers/add_turbo_fish.rs
@@ -41,7 +41,7 @@ pub(crate) fn add_turbo_fish(acc: &mut Assists, ctx: &AssistContext) -> Option<(
    let name_ref = ast::NameRef::cast(ident.parent())?;
    let def = match classify_name_ref(&ctx.sema, &name_ref)? {
        NameRefClass::Definition(def) => def,
-        NameRefClass::FieldShorthand { .. } => return None,
+        NameRefClass::ExternCrate(_) | NameRefClass::FieldShorthand { .. } => return None,
    };
    let fun = match def {
        Definition::ModuleDef(hir::ModuleDef::Function(it)) => it,
diff --git a/crates/ra_assists/src/handlers/apply_demorgan.rs b/crates/ra_assists/src/handlers/apply_demorgan.rs
index de701f8b8..3ac4aed7d 100644
--- a/crates/ra_assists/src/handlers/apply_demorgan.rs
+++ b/crates/ra_assists/src/handlers/apply_demorgan.rs
@@ -4,7 +4,7 @@ use crate::{utils::invert_boolean_expression, AssistContext, AssistId, AssistKin
 // Assist: apply_demorgan
 //
-// Apply [De Morgan's law](https://en.wikipedia.org/wiki/De_Morgan%27s_laws).
+// Apply https://en.wikipedia.org/wiki/De_Morgan%27s_laws[De Morgan's law].
 // This transforms expressions of the form `!l || !r` into `!(l && r)`.
 // This also works with `&&`. This assist can only be applied with the cursor
 // on either `||` or `&&`, with both operands being a negation of some kind.
diff --git a/crates/ra_assists/src/handlers/fix_visibility.rs b/crates/ra_assists/src/handlers/fix_visibility.rs
index 1aefa79cc..a19dbf33f 100644
--- a/crates/ra_assists/src/handlers/fix_visibility.rs
+++ b/crates/ra_assists/src/handlers/fix_visibility.rs
@@ -121,7 +121,7 @@ fn add_vis_to_referenced_record_field(acc: &mut Assists, ctx: &AssistContext) ->
            Some(cap) => match current_visibility {
                Some(current_visibility) => builder.replace_snippet(
                    cap,
-                    dbg!(current_visibility.syntax()).text_range(),
+                    current_visibility.syntax().text_range(),
                    format!("$0{}", missing_visibility),
                ),
                None => builder.insert_snippet(cap, offset, format!("$0{} ", missing_visibility)),
diff --git a/crates/ra_assists/src/handlers/generate_impl.rs b/crates/ra_assists/src/handlers/generate_impl.rs
index d9b87c9c0..7162dc184 100644
--- a/crates/ra_assists/src/handlers/generate_impl.rs
+++ b/crates/ra_assists/src/handlers/generate_impl.rs
@@ -1,5 +1,6 @@
+use itertools::Itertools;
 use ra_syntax::ast::{self, AstNode, GenericParamsOwner, NameOwner};
-use stdx::{format_to, SepBy};
+use stdx::format_to;
 use crate::{AssistContext, AssistId, AssistKind, Assists};
@@ -50,7 +51,7 @@ pub(crate) fn generate_impl(acc: &mut Assists, ctx: &AssistContext) -> Option<()
                    .filter_map(|it| it.name())
                    .map(|it| it.text().clone());
-                let generic_params = lifetime_params.chain(type_params).sep_by(", ");
+                let generic_params = lifetime_params.chain(type_params).format(", ");
                format_to!(buf, "<{}>", generic_params)
            }
            match ctx.config.snippet_cap {
diff --git a/crates/ra_assists/src/handlers/generate_new.rs b/crates/ra_assists/src/handlers/generate_new.rs
index b84aa24b6..32dfed274 100644
--- a/crates/ra_assists/src/handlers/generate_new.rs
+++ b/crates/ra_assists/src/handlers/generate_new.rs
@@ -1,9 +1,10 @@
 use hir::Adt;
+use itertools::Itertools;
 use ra_syntax::{
    ast::{self, AstNode, GenericParamsOwner, NameOwner, StructKind, VisibilityOwner},
    T,
 };
-use stdx::{format_to, SepBy};
+use stdx::format_to;
 use crate::{AssistContext, AssistId, AssistKind, Assists};
@@ -52,8 +53,8 @@ pub(crate) fn generate_new(acc: &mut Assists, ctx: &AssistContext) -> Option<()>
        let params = field_list
            .fields()
            .filter_map(|f| Some(format!("{}: {}", f.name()?.syntax(), f.ty()?.syntax())))
-            .sep_by(", ");
+            .format(", ");
-        let fields = field_list.fields().filter_map(|f| f.name()).sep_by(", ");
+        let fields = field_list.fields().filter_map(|f| f.name()).format(", ");
        format_to!(buf, "    {}fn new({}) -> Self {{ Self {{ {} }} }}", vis, params, fields);
@@ -102,7 +103,7 @@ fn generate_impl_text(strukt: &ast::Struct, code: &str) -> String {
            .map(|it| it.text().clone());
        let type_params =
            type_params.type_params().filter_map(|it| it.name()).map(|it| it.text().clone());
-        format_to!(buf, "<{}>", lifetime_params.chain(type_params).sep_by(", "))
+        format_to!(buf, "<{}>", lifetime_params.chain(type_params).format(", "))
    }
    format_to!(buf, " {{\n{}\n}}\n", code);
diff --git a/crates/ra_assists/src/lib.rs b/crates/ra_assists/src/lib.rs
index 507646cc8..890996a68 100644
--- a/crates/ra_assists/src/lib.rs
+++ b/crates/ra_assists/src/lib.rs
@@ -66,13 +66,13 @@ pub struct GroupLabel(pub String);
 #[derive(Debug, Clone)]
 pub struct Assist {
-    pub id: AssistId,
+    id: AssistId,
    /// Short description of the assist, as shown in the UI.
-    pub label: String,
+    label: String,
-    pub group: Option<GroupLabel>,
+    group: Option<GroupLabel>,
    /// Target ranges are used to sort assists: the smaller the target range,
    /// the more specific assist is, and so it should be sorted first.
-    pub target: TextRange,
+    target: TextRange,
 }
 #[derive(Debug, Clone)]
@@ -120,10 +120,25 @@ impl Assist {
        group: Option<GroupLabel>,
        target: TextRange,
    ) -> Assist {
-        // FIXME: make fields private, so that this invariant can't be broken
        assert!(label.starts_with(|c: char| c.is_uppercase()));
        Assist { id, label, group, target }
    }
+    pub fn id(&self) -> AssistId {
+        self.id
+    }
+    pub fn label(&self) -> String {
+        self.label.clone()
+    }
+    pub fn group(&self) -> Option<GroupLabel> {
+        self.group.clone()
+    }
+    pub fn target(&self) -> TextRange {
+        self.target
+    }
 }
 mod handlers {
diff --git a/crates/ra_assists/src/tests.rs b/crates/ra_assists/src/tests.rs
index 18fcb9049..e73836422 100644
--- a/crates/ra_assists/src/tests.rs
+++ b/crates/ra_assists/src/tests.rs
@@ -20,7 +20,7 @@ pub(crate) fn check_assist(assist: Handler, ra_fixture_before: &str, ra_fixture_
 // FIXME: instead of having a separate function here, maybe use
 // `extract_ranges` and mark the target as `<target> </target>` in the
-// fixuture?
+// fixture?
 pub(crate) fn check_assist_target(assist: Handler, ra_fixture: &str, target: &str) {
    check(assist, ra_fixture, ExpectedResult::Target(target));
 }
diff --git a/crates/ra_assists/src/utils.rs b/crates/ra_assists/src/utils.rs
index 54d5678d1..0de6fdf3f 100644
--- a/crates/ra_assists/src/utils.rs
+++ b/crates/ra_assists/src/utils.rs
@@ -257,7 +257,7 @@ pub use prelude::*;
            .find(|dep| &dep.name.to_string() == std_crate)?
            .krate;
-        let mut module = std_crate.root_module(db)?;
+        let mut module = std_crate.root_module(db);
        for segment in path {
            module = module.children(db).find_map(|child| {
                let name = child.name(db)?;
diff --git a/crates/ra_hir/src/code_model.rs b/crates/ra_hir/src/code_model.rs
index 27cdabea0..0007d7fa8 100644
--- a/crates/ra_hir/src/code_model.rs
+++ b/crates/ra_hir/src/code_model.rs
@@ -4,6 +4,7 @@ use std::{iter, sync::Arc};
 use arrayvec::ArrayVec;
 use either::Either;
 use hir_def::{
+    adt::ReprKind,
    adt::StructKind,
    adt::VariantData,
    builtin_type::BuiltinType,
@@ -83,9 +84,9 @@ impl Crate {
            .collect()
    }
-    pub fn root_module(self, db: &dyn HirDatabase) -> Option<Module> {
+    pub fn root_module(self, db: &dyn HirDatabase) -> Module {
        let module_id = db.crate_def_map(self.id).root;
-        Some(Module::new(self, module_id))
+        Module::new(self, module_id)
    }
    pub fn root_file(self, db: &dyn HirDatabase) -> FileId {
@@ -431,6 +432,10 @@ impl Struct {
        Type::from_def(db, self.id.lookup(db.upcast()).container.module(db.upcast()).krate, self.id)
    }
+    pub fn repr(self, db: &dyn HirDatabase) -> Option<ReprKind> {
+        db.struct_data(self.id).repr.clone()
+    }
    fn variant_data(self, db: &dyn HirDatabase) -> Arc<VariantData> {
        db.struct_data(self.id).variant_data.clone()
    }
@@ -1253,6 +1258,19 @@ impl Type {
        )
    }
+    pub fn is_packed(&self, db: &dyn HirDatabase) -> bool {
+        let adt_id = match self.ty.value {
+            Ty::Apply(ApplicationTy { ctor: TypeCtor::Adt(adt_id), .. }) => adt_id,
+            _ => return false,
+        };
+        let adt = adt_id.into();
+        match adt {
+            Adt::Struct(s) => matches!(s.repr(db), Some(ReprKind::Packed)),
+            _ => false,
+        }
+    }
    pub fn is_raw_ptr(&self) -> bool {
        matches!(&self.ty.value, Ty::Apply(ApplicationTy { ctor: TypeCtor::RawPtr(..), .. }))
    }
diff --git a/crates/ra_hir/src/diagnostics.rs b/crates/ra_hir/src/diagnostics.rs
index 266b513dc..363164b9b 100644
--- a/crates/ra_hir/src/diagnostics.rs
+++ b/crates/ra_hir/src/diagnostics.rs
@@ -1,8 +1,6 @@
 //! FIXME: write short doc here
 pub use hir_def::diagnostics::UnresolvedModule;
-pub use hir_expand::diagnostics::{
+pub use hir_expand::diagnostics::{Diagnostic, DiagnosticSink, DiagnosticSinkBuilder};
-    AstDiagnostic, Diagnostic, DiagnosticSink, DiagnosticSinkBuilder,
-};
 pub use hir_ty::diagnostics::{
    MismatchedArgCount, MissingFields, MissingMatchArms, MissingOkInTailExpr, NoSuchField,
 };
diff --git a/crates/ra_hir/src/lib.rs b/crates/ra_hir/src/lib.rs
index 31f3241c9..34b02c536 100644
--- a/crates/ra_hir/src/lib.rs
+++ b/crates/ra_hir/src/lib.rs
@@ -49,7 +49,7 @@ pub use hir_def::{
    docs::Documentation,
    nameres::ModuleSource,
    path::{ModPath, Path, PathKind},
-    type_ref::Mutability,
+    type_ref::{Mutability, TypeRef},
 };
 pub use hir_expand::{
    hygiene::Hygiene, name::Name, HirFileId, InFile, MacroCallId, MacroCallLoc,
diff --git a/crates/ra_hir/src/semantics.rs b/crates/ra_hir/src/semantics.rs
index 307b336f2..36b688ccb 100644
--- a/crates/ra_hir/src/semantics.rs
+++ b/crates/ra_hir/src/semantics.rs
@@ -8,7 +8,7 @@ use hir_def::{
    resolver::{self, HasResolver, Resolver},
    AsMacroCall, FunctionId, TraitId, VariantId,
 };
-use hir_expand::{diagnostics::AstDiagnostic, hygiene::Hygiene, ExpansionInfo};
+use hir_expand::{hygiene::Hygiene, name::AsName, ExpansionInfo};
 use hir_ty::associated_type_shorthand_candidates;
 use itertools::Itertools;
 use ra_db::{FileId, FileRange};
@@ -24,8 +24,9 @@ use crate::{
    diagnostics::Diagnostic,
    semantics::source_to_def::{ChildContainer, SourceToDefCache, SourceToDefCtx},
    source_analyzer::{resolve_hir_path, resolve_hir_path_qualifier, SourceAnalyzer},
-    AssocItem, Callable, Field, Function, HirFileId, ImplDef, InFile, Local, MacroDef, Module,
+    AssocItem, Callable, Crate, Field, Function, HirFileId, ImplDef, InFile, Local, MacroDef,
-    ModuleDef, Name, Origin, Path, ScopeDef, Trait, Type, TypeAlias, TypeParam, VariantDef,
+    Module, ModuleDef, Name, Origin, Path, ScopeDef, Trait, Type, TypeAlias, TypeParam, TypeRef,
+    VariantDef,
 };
 use resolver::TypeNs;
@@ -109,13 +110,6 @@ impl<'db, DB: HirDatabase> Semantics<'db, DB> {
        self.imp.parse(file_id)
    }
-    pub fn ast<T: AstDiagnostic + Diagnostic>(&self, d: &T) -> <T as AstDiagnostic>::AST {
-        let file_id = d.source().file_id;
-        let root = self.db.parse_or_expand(file_id).unwrap();
-        self.imp.cache(root, file_id);
-        d.ast(self.db.upcast())
-    }
    pub fn expand(&self, macro_call: &ast::MacroCall) -> Option<SyntaxNode> {
        self.imp.expand(macro_call)
    }
@@ -145,8 +139,8 @@ impl<'db, DB: HirDatabase> Semantics<'db, DB> {
        self.imp.original_range(node)
    }
-    pub fn diagnostics_range(&self, diagnostics: &dyn Diagnostic) -> FileRange {
+    pub fn diagnostics_display_range(&self, diagnostics: &dyn Diagnostic) -> FileRange {
-        self.imp.diagnostics_range(diagnostics)
+        self.imp.diagnostics_display_range(diagnostics)
    }
    pub fn ancestors_with_macros(&self, node: SyntaxNode) -> impl Iterator<Item = SyntaxNode> + '_ {
@@ -228,6 +222,10 @@ impl<'db, DB: HirDatabase> Semantics<'db, DB> {
        self.imp.resolve_path(path)
    }
+    pub fn resolve_extern_crate(&self, extern_crate: &ast::ExternCrate) -> Option<Crate> {
+        self.imp.resolve_extern_crate(extern_crate)
+    }
    pub fn resolve_variant(&self, record_lit: ast::RecordExpr) -> Option<VariantDef> {
        self.imp.resolve_variant(record_lit).map(VariantDef::from)
    }
@@ -275,6 +273,18 @@ impl<'db, DB: HirDatabase> Semantics<'db, DB> {
    pub fn assert_contains_node(&self, node: &SyntaxNode) {
        self.imp.assert_contains_node(node)
    }
+    pub fn is_unsafe_method_call(&self, method_call_expr: ast::MethodCallExpr) -> bool {
+        self.imp.is_unsafe_method_call(method_call_expr)
+    }
+    pub fn is_unsafe_ref_expr(&self, ref_expr: &ast::RefExpr) -> bool {
+        self.imp.is_unsafe_ref_expr(ref_expr)
+    }
+    pub fn is_unsafe_ident_pat(&self, ident_pat: &ast::IdentPat) -> bool {
+        self.imp.is_unsafe_ident_pat(ident_pat)
+    }
 }
 impl<'db> SemanticsImpl<'db> {
@@ -372,10 +382,11 @@ impl<'db> SemanticsImpl<'db> {
        original_range(self.db, node.as_ref())
    }
-    fn diagnostics_range(&self, diagnostics: &dyn Diagnostic) -> FileRange {
+    fn diagnostics_display_range(&self, diagnostics: &dyn Diagnostic) -> FileRange {
-        let src = diagnostics.source();
+        let src = diagnostics.display_source();
        let root = self.db.parse_or_expand(src.file_id).unwrap();
        let node = src.value.to_node(&root);
+        self.cache(root, src.file_id);
        original_range(self.db, src.with_value(&node))
    }
@@ -443,6 +454,17 @@ impl<'db> SemanticsImpl<'db> {
        self.analyze(path.syntax()).resolve_path(self.db, path)
    }
+    fn resolve_extern_crate(&self, extern_crate: &ast::ExternCrate) -> Option<Crate> {
+        let krate = self.scope(extern_crate.syntax()).krate()?;
+        krate.dependencies(self.db).into_iter().find_map(|dep| {
+            if dep.name == extern_crate.name_ref()?.as_name() {
+                Some(dep.krate)
+            } else {
+                None
+            }
+        })
+    }
    fn resolve_variant(&self, record_lit: ast::RecordExpr) -> Option<VariantId> {
        self.analyze(record_lit.syntax()).resolve_variant(self.db, record_lit)
    }
@@ -559,6 +581,90 @@ impl<'db> SemanticsImpl<'db> {
        });
        InFile::new(file_id, node)
    }
+    pub fn is_unsafe_method_call(&self, method_call_expr: ast::MethodCallExpr) -> bool {
+        method_call_expr
+            .expr()
+            .and_then(|expr| {
+                let field_expr = if let ast::Expr::FieldExpr(field_expr) = expr {
+                    field_expr
+                } else {
+                    return None;
+                };
+                let ty = self.type_of_expr(&field_expr.expr()?)?;
+                if !ty.is_packed(self.db) {
+                    return None;
+                }
+                let func = self.resolve_method_call(&method_call_expr).map(Function::from)?;
+                let is_unsafe = func.has_self_param(self.db)
+                    && matches!(func.params(self.db).first(), Some(TypeRef::Reference(..)));
+                Some(is_unsafe)
+            })
+            .unwrap_or(false)
+    }
+    pub fn is_unsafe_ref_expr(&self, ref_expr: &ast::RefExpr) -> bool {
+        ref_expr
+            .expr()
+            .and_then(|expr| {
+                let field_expr = match expr {
+                    ast::Expr::FieldExpr(field_expr) => field_expr,
+                    _ => return None,
+                };
+                let expr = field_expr.expr()?;
+                self.type_of_expr(&expr)
+            })
+            // Binding a reference to a packed type is possibly unsafe.
+            .map(|ty| ty.is_packed(self.db))
+            .unwrap_or(false)
+        // FIXME This needs layout computation to be correct. It will highlight
+        // more than it should with the current implementation.
+    }
+    pub fn is_unsafe_ident_pat(&self, ident_pat: &ast::IdentPat) -> bool {
+        if !ident_pat.ref_token().is_some() {
+            return false;
+        }
+        ident_pat
+            .syntax()
+            .parent()
+            .and_then(|parent| {
+                // `IdentPat` can live under `RecordPat` directly under `RecordPatField` or
+                // `RecordPatFieldList`. `RecordPatField` also lives under `RecordPatFieldList`,
+                // so this tries to lookup the `IdentPat` anywhere along that structure to the
+                // `RecordPat` so we can get the containing type.
+                let record_pat = ast::RecordPatField::cast(parent.clone())
+                    .and_then(|record_pat| record_pat.syntax().parent())
+                    .or_else(|| Some(parent.clone()))
+                    .and_then(|parent| {
+                        ast::RecordPatFieldList::cast(parent)?
+                            .syntax()
+                            .parent()
+                            .and_then(ast::RecordPat::cast)
+                    });
+                // If this doesn't match a `RecordPat`, fallback to a `LetStmt` to see if
+                // this is initialized from a `FieldExpr`.
+                if let Some(record_pat) = record_pat {
+                    self.type_of_pat(&ast::Pat::RecordPat(record_pat))
+                } else if let Some(let_stmt) = ast::LetStmt::cast(parent) {
+                    let field_expr = match let_stmt.initializer()? {
+                        ast::Expr::FieldExpr(field_expr) => field_expr,
+                        _ => return None,
+                    };
+                    self.type_of_expr(&field_expr.expr()?)
+                } else {
+                    None
+                }
+            })
+            // Binding a reference to a packed type is possibly unsafe.
+            .map(|ty| ty.is_packed(self.db))
+            .unwrap_or(false)
+    }
 }
 pub trait ToDef: AstNode + Clone {
@@ -612,6 +718,10 @@ impl<'a> SemanticsScope<'a> {
        Some(Module { id: self.resolver.module()? })
    }
+    pub fn krate(&self) -> Option<Crate> {
+        Some(Crate { id: self.resolver.krate()? })
+    }
    /// Note: `FxHashSet<TraitId>` should be treated as an opaque type, passed into `Type
    // FIXME: rename to visible_traits to not repeat scope?
    pub fn traits_in_scope(&self) -> FxHashSet<TraitId> {
diff --git a/crates/ra_hir/src/source_analyzer.rs b/crates/ra_hir/src/source_analyzer.rs
index d0cb62ef0..d3d62debf 100644
--- a/crates/ra_hir/src/source_analyzer.rs
+++ b/crates/ra_hir/src/source_analyzer.rs
@@ -265,8 +265,7 @@ impl SourceAnalyzer {
        }
        // This must be a normal source file rather than macro file.
-        let hir_path =
+        let hir_path = Path::from_src(path.clone(), &Hygiene::new(db.upcast(), self.file_id))?;
-            crate::Path::from_src(path.clone(), &Hygiene::new(db.upcast(), self.file_id))?;
        // Case where path is a qualifier of another path, e.g. foo::bar::Baz where we
        // trying to resolve foo::bar.
@@ -451,7 +450,7 @@ fn adjust(
 pub(crate) fn resolve_hir_path(
    db: &dyn HirDatabase,
    resolver: &Resolver,
-    path: &crate::Path,
+    path: &Path,
 ) -> Option<PathResolution> {
    let types =
        resolver.resolve_path_in_type_ns_fully(db.upcast(), path.mod_path()).map(|ty| match ty {
@@ -512,7 +511,7 @@ pub(crate) fn resolve_hir_path(
 pub(crate) fn resolve_hir_path_qualifier(
    db: &dyn HirDatabase,
    resolver: &Resolver,
-    path: &crate::Path,
+    path: &Path,
 ) -> Option<PathResolution> {
    let items = resolver
        .resolve_module_path_in_items(db.upcast(), path.mod_path())
diff --git a/crates/ra_hir_def/src/adt.rs b/crates/ra_hir_def/src/adt.rs
index 6cb56a1cd..35c3a9140 100644
--- a/crates/ra_hir_def/src/adt.rs
+++ b/crates/ra_hir_def/src/adt.rs
@@ -9,11 +9,12 @@ use hir_expand::{
 };
 use ra_arena::{map::ArenaMap, Arena};
 use ra_syntax::ast::{self, NameOwner, VisibilityOwner};
+use tt::{Delimiter, DelimiterKind, Leaf, Subtree, TokenTree};
 use crate::{
    body::{CfgExpander, LowerCtx},
    db::DefDatabase,
-    item_tree::{Field, Fields, ItemTree},
+    item_tree::{AttrOwner, Field, Fields, ItemTree, ModItem},
    src::HasChildSource,
    src::HasSource,
    trace::Trace,
@@ -29,6 +30,7 @@ use ra_cfg::CfgOptions;
 pub struct StructData {
    pub name: Name,
    pub variant_data: Arc<VariantData>,
+    pub repr: Option<ReprKind>,
 }
 #[derive(Debug, Clone, PartialEq, Eq)]
@@ -58,26 +60,58 @@ pub struct FieldData {
    pub visibility: RawVisibility,
 }
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub enum ReprKind {
+    Packed,
+    Other,
+}
+fn repr_from_value(item_tree: &ItemTree, of: AttrOwner) -> Option<ReprKind> {
+    item_tree.attrs(of).by_key("repr").tt_values().find_map(parse_repr_tt)
+}
+fn parse_repr_tt(tt: &Subtree) -> Option<ReprKind> {
+    match tt.delimiter {
+        Some(Delimiter { kind: DelimiterKind::Parenthesis, .. }) => {}
+        _ => return None,
+    }
+    let mut it = tt.token_trees.iter();
+    match it.next()? {
+        TokenTree::Leaf(Leaf::Ident(ident)) if ident.text == "packed" => Some(ReprKind::Packed),
+        _ => Some(ReprKind::Other),
+    }
+}
 impl StructData {
    pub(crate) fn struct_data_query(db: &dyn DefDatabase, id: StructId) -> Arc<StructData> {
        let loc = id.lookup(db);
        let item_tree = db.item_tree(loc.id.file_id);
+        let repr = repr_from_value(&item_tree, ModItem::from(loc.id.value).into());
        let cfg_options = db.crate_graph()[loc.container.module(db).krate].cfg_options.clone();
        let strukt = &item_tree[loc.id.value];
        let variant_data = lower_fields(&item_tree, &cfg_options, &strukt.fields);
+        Arc::new(StructData {
-        Arc::new(StructData { name: strukt.name.clone(), variant_data: Arc::new(variant_data) })
+            name: strukt.name.clone(),
+            variant_data: Arc::new(variant_data),
+            repr,
+        })
    }
    pub(crate) fn union_data_query(db: &dyn DefDatabase, id: UnionId) -> Arc<StructData> {
        let loc = id.lookup(db);
        let item_tree = db.item_tree(loc.id.file_id);
+        let repr = repr_from_value(&item_tree, ModItem::from(loc.id.value).into());
        let cfg_options = db.crate_graph()[loc.container.module(db).krate].cfg_options.clone();
        let union = &item_tree[loc.id.value];
        let variant_data = lower_fields(&item_tree, &cfg_options, &union.fields);
-        Arc::new(StructData { name: union.name.clone(), variant_data: Arc::new(variant_data) })
+        Arc::new(StructData {
+            name: union.name.clone(),
+            variant_data: Arc::new(variant_data),
+            repr,
+        })
    }
 }
diff --git a/crates/ra_hir_def/src/diagnostics.rs b/crates/ra_hir_def/src/diagnostics.rs
index 481b13a87..5b7f05bf4 100644
--- a/crates/ra_hir_def/src/diagnostics.rs
+++ b/crates/ra_hir_def/src/diagnostics.rs
@@ -21,7 +21,7 @@ impl Diagnostic for UnresolvedModule {
    fn message(&self) -> String {
        "unresolved module".to_string()
    }
-    fn source(&self) -> InFile<SyntaxNodePtr> {
+    fn display_source(&self) -> InFile<SyntaxNodePtr> {
        InFile::new(self.file, self.decl.clone().into())
    }
    fn as_any(&self) -> &(dyn Any + Send + 'static) {
diff --git a/crates/ra_hir_expand/src/diagnostics.rs b/crates/ra_hir_expand/src/diagnostics.rs
index 507132a13..a618934c9 100644
--- a/crates/ra_hir_expand/src/diagnostics.rs
+++ b/crates/ra_hir_expand/src/diagnostics.rs
@@ -16,36 +16,21 @@
 use std::{any::Any, fmt};
-use ra_syntax::{SyntaxNode, SyntaxNodePtr};
+use ra_syntax::SyntaxNodePtr;
-use crate::{db::AstDatabase, InFile};
+use crate::InFile;
 pub trait Diagnostic: Any + Send + Sync + fmt::Debug + 'static {
    fn name(&self) -> &'static str;
    fn message(&self) -> String;
-    fn source(&self) -> InFile<SyntaxNodePtr>;
+    /// Used in highlighting and related purposes
+    fn display_source(&self) -> InFile<SyntaxNodePtr>;
    fn as_any(&self) -> &(dyn Any + Send + 'static);
    fn is_experimental(&self) -> bool {
        false
    }
 }
-pub trait AstDiagnostic {
-    type AST;
-    fn ast(&self, db: &dyn AstDatabase) -> Self::AST;
-}
-impl dyn Diagnostic {
-    pub fn syntax_node(&self, db: &impl AstDatabase) -> SyntaxNode {
-        let node = db.parse_or_expand(self.source().file_id).unwrap();
-        self.source().value.to_node(&node)
-    }
-    pub fn downcast_ref<D: Diagnostic>(&self) -> Option<&D> {
-        self.as_any().downcast_ref()
-    }
-}
 pub struct DiagnosticSink<'a> {
    callbacks: Vec<Box<dyn FnMut(&dyn Diagnostic) -> Result<(), ()> + 'a>>,
    filters: Vec<Box<dyn FnMut(&dyn Diagnostic) -> bool + 'a>>,
@@ -90,7 +75,7 @@ impl<'a> DiagnosticSinkBuilder<'a> {
    }
    pub fn on<D: Diagnostic, F: FnMut(&D) + 'a>(mut self, mut cb: F) -> Self {
-        let cb = move |diag: &dyn Diagnostic| match diag.downcast_ref::<D>() {
+        let cb = move |diag: &dyn Diagnostic| match diag.as_any().downcast_ref::<D>() {
            Some(d) => {
                cb(d);
                Ok(())
diff --git a/crates/ra_hir_expand/src/hygiene.rs b/crates/ra_hir_expand/src/hygiene.rs
index 6b482a60c..aefe47bd3 100644
--- a/crates/ra_hir_expand/src/hygiene.rs
+++ b/crates/ra_hir_expand/src/hygiene.rs
@@ -17,7 +17,7 @@ pub struct Hygiene {
    // This is what `$crate` expands to
    def_crate: Option<CrateId>,
-    // Indiciate this is a local inner macro
+    // Indicate this is a local inner macro
    local_inner: bool,
 }
diff --git a/crates/ra_hir_expand/src/lib.rs b/crates/ra_hir_expand/src/lib.rs
index 2e8d63691..8bb735fc6 100644
--- a/crates/ra_hir_expand/src/lib.rs
+++ b/crates/ra_hir_expand/src/lib.rs
@@ -44,7 +44,8 @@ mod test_db;
 /// containing the call plus the offset of the macro call in the file. Note that
 /// this is a recursive definition! However, the size_of of `HirFileId` is
 /// finite (because everything bottoms out at the real `FileId`) and small
-/// (`MacroCallId` uses the location interner).
+/// (`MacroCallId` uses the location interning. You can check details here:
+/// https://en.wikipedia.org/wiki/String_interning).
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 pub struct HirFileId(HirFileIdRepr);
diff --git a/crates/ra_hir_ty/Cargo.toml b/crates/ra_hir_ty/Cargo.toml
index 623ce261a..83397d579 100644
--- a/crates/ra_hir_ty/Cargo.toml
+++ b/crates/ra_hir_ty/Cargo.toml
@@ -28,9 +28,9 @@ test_utils = { path = "../test_utils" }
 scoped-tls = "1"
-chalk-solve = { version = "0.19.0" }
+chalk-solve = { version = "0.21.0" }
-chalk-ir = { version = "0.19.0" }
+chalk-ir = { version = "0.21.0" }
-chalk-recursive = { version = "0.19.0" }
+chalk-recursive = { version = "0.21.0" }
 [dev-dependencies]
 expect = { path = "../expect" }
diff --git a/crates/ra_hir_ty/src/diagnostics.rs b/crates/ra_hir_ty/src/diagnostics.rs
index 56acd3bbf..45e31033e 100644
--- a/crates/ra_hir_ty/src/diagnostics.rs
+++ b/crates/ra_hir_ty/src/diagnostics.rs
@@ -6,10 +6,10 @@ mod unsafe_check;
 use std::any::Any;
 use hir_def::DefWithBodyId;
-use hir_expand::diagnostics::{AstDiagnostic, Diagnostic, DiagnosticSink};
+use hir_expand::diagnostics::{Diagnostic, DiagnosticSink};
-use hir_expand::{db::AstDatabase, name::Name, HirFileId, InFile};
+use hir_expand::{name::Name, HirFileId, InFile};
 use ra_prof::profile;
-use ra_syntax::{ast, AstNode, AstPtr, SyntaxNodePtr};
+use ra_syntax::{ast, AstPtr, SyntaxNodePtr};
 use stdx::format_to;
 use crate::db::HirDatabase;
@@ -41,7 +41,7 @@ impl Diagnostic for NoSuchField {
        "no such field".to_string()
    }
-    fn source(&self) -> InFile<SyntaxNodePtr> {
+    fn display_source(&self) -> InFile<SyntaxNodePtr> {
        InFile::new(self.file, self.field.clone().into())
    }
@@ -50,20 +50,11 @@ impl Diagnostic for NoSuchField {
    }
 }
-impl AstDiagnostic for NoSuchField {
-    type AST = ast::RecordExprField;
-    fn ast(&self, db: &dyn AstDatabase) -> Self::AST {
-        let root = db.parse_or_expand(self.source().file_id).unwrap();
-        let node = self.source().value.to_node(&root);
-        ast::RecordExprField::cast(node).unwrap()
-    }
-}
 #[derive(Debug)]
 pub struct MissingFields {
    pub file: HirFileId,
-    pub field_list: AstPtr<ast::RecordExprFieldList>,
+    pub field_list_parent: AstPtr<ast::RecordExpr>,
+    pub field_list_parent_path: Option<AstPtr<ast::Path>>,
    pub missed_fields: Vec<Name>,
 }
@@ -78,28 +69,28 @@ impl Diagnostic for MissingFields {
        }
        buf
    }
-    fn source(&self) -> InFile<SyntaxNodePtr> {
-        InFile { file_id: self.file, value: self.field_list.clone().into() }
+    fn display_source(&self) -> InFile<SyntaxNodePtr> {
+        InFile {
+            file_id: self.file,
+            value: self
+                .field_list_parent_path
+                .clone()
+                .map(SyntaxNodePtr::from)
+                .unwrap_or_else(|| self.field_list_parent.clone().into()),
+        }
    }
    fn as_any(&self) -> &(dyn Any + Send + 'static) {
        self
    }
 }
-impl AstDiagnostic for MissingFields {
-    type AST = ast::RecordExprFieldList;
-    fn ast(&self, db: &dyn AstDatabase) -> Self::AST {
-        let root = db.parse_or_expand(self.source().file_id).unwrap();
-        let node = self.source().value.to_node(&root);
-        ast::RecordExprFieldList::cast(node).unwrap()
-    }
-}
 #[derive(Debug)]
 pub struct MissingPatFields {
    pub file: HirFileId,
-    pub field_list: AstPtr<ast::RecordPatFieldList>,
+    pub field_list_parent: AstPtr<ast::RecordPat>,
+    pub field_list_parent_path: Option<AstPtr<ast::Path>>,
    pub missed_fields: Vec<Name>,
 }
@@ -114,8 +105,15 @@ impl Diagnostic for MissingPatFields {
        }
        buf
    }
-    fn source(&self) -> InFile<SyntaxNodePtr> {
+    fn display_source(&self) -> InFile<SyntaxNodePtr> {
-        InFile { file_id: self.file, value: self.field_list.clone().into() }
+        InFile {
+            file_id: self.file,
+            value: self
+                .field_list_parent_path
+                .clone()
+                .map(SyntaxNodePtr::from)
+                .unwrap_or_else(|| self.field_list_parent.clone().into()),
+        }
    }
    fn as_any(&self) -> &(dyn Any + Send + 'static) {
        self
@@ -136,7 +134,7 @@ impl Diagnostic for MissingMatchArms {
    fn message(&self) -> String {
        String::from("Missing match arm")
    }
-    fn source(&self) -> InFile<SyntaxNodePtr> {
+    fn display_source(&self) -> InFile<SyntaxNodePtr> {
        InFile { file_id: self.file, value: self.match_expr.clone().into() }
    }
    fn as_any(&self) -> &(dyn Any + Send + 'static) {
@@ -157,7 +155,7 @@ impl Diagnostic for MissingOkInTailExpr {
    fn message(&self) -> String {
        "wrap return expression in Ok".to_string()
    }
-    fn source(&self) -> InFile<SyntaxNodePtr> {
+    fn display_source(&self) -> InFile<SyntaxNodePtr> {
        InFile { file_id: self.file, value: self.expr.clone().into() }
    }
    fn as_any(&self) -> &(dyn Any + Send + 'static) {
@@ -165,16 +163,6 @@ impl Diagnostic for MissingOkInTailExpr {
    }
 }
-impl AstDiagnostic for MissingOkInTailExpr {
-    type AST = ast::Expr;
-    fn ast(&self, db: &dyn AstDatabase) -> Self::AST {
-        let root = db.parse_or_expand(self.file).unwrap();
-        let node = self.source().value.to_node(&root);
-        ast::Expr::cast(node).unwrap()
-    }
-}
 #[derive(Debug)]
 pub struct BreakOutsideOfLoop {
    pub file: HirFileId,
@@ -188,7 +176,7 @@ impl Diagnostic for BreakOutsideOfLoop {
    fn message(&self) -> String {
        "break outside of loop".to_string()
    }
-    fn source(&self) -> InFile<SyntaxNodePtr> {
+    fn display_source(&self) -> InFile<SyntaxNodePtr> {
        InFile { file_id: self.file, value: self.expr.clone().into() }
    }
    fn as_any(&self) -> &(dyn Any + Send + 'static) {
@@ -196,16 +184,6 @@ impl Diagnostic for BreakOutsideOfLoop {
    }
 }
-impl AstDiagnostic for BreakOutsideOfLoop {
-    type AST = ast::Expr;
-    fn ast(&self, db: &dyn AstDatabase) -> Self::AST {
-        let root = db.parse_or_expand(self.file).unwrap();
-        let node = self.source().value.to_node(&root);
-        ast::Expr::cast(node).unwrap()
-    }
-}
 #[derive(Debug)]
 pub struct MissingUnsafe {
    pub file: HirFileId,
@@ -219,7 +197,7 @@ impl Diagnostic for MissingUnsafe {
    fn message(&self) -> String {
        format!("This operation is unsafe and requires an unsafe function or block")
    }
-    fn source(&self) -> InFile<SyntaxNodePtr> {
+    fn display_source(&self) -> InFile<SyntaxNodePtr> {
        InFile { file_id: self.file, value: self.expr.clone().into() }
    }
    fn as_any(&self) -> &(dyn Any + Send + 'static) {
@@ -227,16 +205,6 @@ impl Diagnostic for MissingUnsafe {
    }
 }
-impl AstDiagnostic for MissingUnsafe {
-    type AST = ast::Expr;
-    fn ast(&self, db: &dyn AstDatabase) -> Self::AST {
-        let root = db.parse_or_expand(self.source().file_id).unwrap();
-        let node = self.source().value.to_node(&root);
-        ast::Expr::cast(node).unwrap()
-    }
-}
 #[derive(Debug)]
 pub struct MismatchedArgCount {
    pub file: HirFileId,
@@ -253,7 +221,7 @@ impl Diagnostic for MismatchedArgCount {
        let s = if self.expected == 1 { "" } else { "s" };
        format!("Expected {} argument{}, found {}", self.expected, s, self.found)
    }
-    fn source(&self) -> InFile<SyntaxNodePtr> {
+    fn display_source(&self) -> InFile<SyntaxNodePtr> {
        InFile { file_id: self.file, value: self.call_expr.clone().into() }
    }
    fn as_any(&self) -> &(dyn Any + Send + 'static) {
@@ -264,19 +232,13 @@ impl Diagnostic for MismatchedArgCount {
    }
 }
-impl AstDiagnostic for MismatchedArgCount {
-    type AST = ast::CallExpr;
-    fn ast(&self, db: &dyn AstDatabase) -> Self::AST {
-        let root = db.parse_or_expand(self.source().file_id).unwrap();
-        let node = self.source().value.to_node(&root);
-        ast::CallExpr::cast(node).unwrap()
-    }
-}
 #[cfg(test)]
 mod tests {
    use hir_def::{db::DefDatabase, AssocItemId, ModuleDefId};
-    use hir_expand::diagnostics::{Diagnostic, DiagnosticSinkBuilder};
+    use hir_expand::{
+        db::AstDatabase,
+        diagnostics::{Diagnostic, DiagnosticSinkBuilder},
+    };
    use ra_db::{fixture::WithFixture, FileId, SourceDatabase, SourceDatabaseExt};
    use ra_syntax::{TextRange, TextSize};
    use rustc_hash::FxHashMap;
@@ -321,9 +283,11 @@ mod tests {
        let mut actual: FxHashMap<FileId, Vec<(TextRange, String)>> = FxHashMap::default();
        db.diagnostics(|d| {
-            // FXIME: macros...
+            let src = d.display_source();
-            let file_id = d.source().file_id.original_file(&db);
+            let root = db.parse_or_expand(src.file_id).unwrap();
-            let range = d.syntax_node(&db).text_range();
+            // FIXME: macros...
+            let file_id = src.file_id.original_file(&db);
+            let range = src.value.to_node(&root).text_range();
            let message = d.message().to_owned();
            actual.entry(file_id).or_default().push((range, message));
        });
@@ -351,8 +315,8 @@ struct S { foo: i32, bar: () }
 impl S {
    fn new() -> S {
        S {
-        //^... Missing structure fields:
+      //^ Missing structure fields:
-        //|    - bar
+      //|    - bar
            foo: 92,
            baz: 62,
          //^^^^^^^ no such field
@@ -473,8 +437,8 @@ impl Foo {
 struct S { foo: i32, bar: () }
 fn baz(s: S) {
    let S { foo: _ } = s;
-        //^^^^^^^^^^ Missing structure fields:
+      //^ Missing structure fields:
-        //         | - bar
+      //| - bar
 }
 "#,
        );
diff --git a/crates/ra_hir_ty/src/diagnostics/expr.rs b/crates/ra_hir_ty/src/diagnostics/expr.rs
index 95bbf2d95..51adcecaf 100644
--- a/crates/ra_hir_ty/src/diagnostics/expr.rs
+++ b/crates/ra_hir_ty/src/diagnostics/expr.rs
@@ -100,8 +100,8 @@ impl<'a, 'b> ExprValidator<'a, 'b> {
        if let Ok(source_ptr) = source_map.expr_syntax(id) {
            let root = source_ptr.file_syntax(db.upcast());
-            if let ast::Expr::RecordExpr(record_lit) = &source_ptr.value.to_node(&root) {
+            if let ast::Expr::RecordExpr(record_expr) = &source_ptr.value.to_node(&root) {
-                if let Some(field_list) = record_lit.record_expr_field_list() {
+                if let Some(_) = record_expr.record_expr_field_list() {
                    let variant_data = variant_data(db.upcast(), variant_def);
                    let missed_fields = missed_fields
                        .into_iter()
@@ -109,7 +109,8 @@ impl<'a, 'b> ExprValidator<'a, 'b> {
                        .collect();
                    self.sink.push(MissingFields {
                        file: source_ptr.file_id,
-                        field_list: AstPtr::new(&field_list),
+                        field_list_parent: AstPtr::new(&record_expr),
+                        field_list_parent_path: record_expr.path().map(|path| AstPtr::new(&path)),
                        missed_fields,
                    })
                }
@@ -131,7 +132,7 @@ impl<'a, 'b> ExprValidator<'a, 'b> {
            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(field_list) = record_pat.record_pat_field_list() {
+                    if let Some(_) = record_pat.record_pat_field_list() {
                        let variant_data = variant_data(db.upcast(), variant_def);
                        let missed_fields = missed_fields
                            .into_iter()
@@ -139,7 +140,10 @@ impl<'a, 'b> ExprValidator<'a, 'b> {
                            .collect();
                        self.sink.push(MissingPatFields {
                            file: source_ptr.file_id,
-                            field_list: AstPtr::new(&field_list),
+                            field_list_parent: AstPtr::new(&record_pat),
+                            field_list_parent_path: record_pat
+                                .path()
+                                .map(|path| AstPtr::new(&path)),
                            missed_fields,
                        })
                    }
diff --git a/crates/ra_hir_ty/src/diagnostics/match_check.rs b/crates/ra_hir_ty/src/diagnostics/match_check.rs
index 507edcb7d..deca244db 100644
--- a/crates/ra_hir_ty/src/diagnostics/match_check.rs
+++ b/crates/ra_hir_ty/src/diagnostics/match_check.rs
@@ -1161,15 +1161,15 @@ fn main() {
        //^ Missing match arm
    match a {
        Either::A { } => (),
-                //^^^ Missing structure fields:
+      //^^^^^^^^^ Missing structure fields:
-                //  | - foo
+      //        | - foo
        Either::B => (),
    }
    match a {
        //^ Missing match arm
        Either::A { } => (),
-    }           //^^^ Missing structure fields:
+    } //^^^^^^^^^ Missing structure fields:
-                //  | - foo
+      //        | - foo
    match a {
        Either::A { foo: true } => (),
diff --git a/crates/ra_hir_ty/src/diagnostics/unsafe_check.rs b/crates/ra_hir_ty/src/diagnostics/unsafe_check.rs
index 5cc76bdce..61ffbf5d1 100644
--- a/crates/ra_hir_ty/src/diagnostics/unsafe_check.rs
+++ b/crates/ra_hir_ty/src/diagnostics/unsafe_check.rs
@@ -6,6 +6,7 @@ use std::sync::Arc;
 use hir_def::{
    body::Body,
    expr::{Expr, ExprId, UnaryOp},
+    resolver::{resolver_for_expr, ResolveValueResult, ValueNs},
    DefWithBodyId,
 };
 use hir_expand::diagnostics::DiagnosticSink;
@@ -70,7 +71,7 @@ pub fn unsafe_expressions(
 ) -> Vec<UnsafeExpr> {
    let mut unsafe_exprs = vec![];
    let body = db.body(def);
-    walk_unsafe(&mut unsafe_exprs, db, infer, &body, body.body_expr, false);
+    walk_unsafe(&mut unsafe_exprs, db, infer, def, &body, body.body_expr, false);
    unsafe_exprs
 }
@@ -79,6 +80,7 @@ fn walk_unsafe(
    unsafe_exprs: &mut Vec<UnsafeExpr>,
    db: &dyn HirDatabase,
    infer: &InferenceResult,
+    def: DefWithBodyId,
    body: &Body,
    current: ExprId,
    inside_unsafe_block: bool,
@@ -97,6 +99,15 @@ fn walk_unsafe(
                }
            }
        }
+        Expr::Path(path) => {
+            let resolver = resolver_for_expr(db.upcast(), def, current);
+            let value_or_partial = resolver.resolve_path_in_value_ns(db.upcast(), path.mod_path());
+            if let Some(ResolveValueResult::ValueNs(ValueNs::StaticId(id))) = value_or_partial {
+                if db.static_data(id).mutable {
+                    unsafe_exprs.push(UnsafeExpr { expr: current, inside_unsafe_block });
+                }
+            }
+        }
        Expr::MethodCall { .. } => {
            if infer
                .method_resolution(current)
@@ -112,13 +123,13 @@ fn walk_unsafe(
            }
        }
        Expr::Unsafe { body: child } => {
-            return walk_unsafe(unsafe_exprs, db, infer, body, *child, true);
+            return walk_unsafe(unsafe_exprs, db, infer, def, body, *child, true);
        }
        _ => {}
    }
    expr.walk_child_exprs(|child| {
-        walk_unsafe(unsafe_exprs, db, infer, body, child, inside_unsafe_block);
+        walk_unsafe(unsafe_exprs, db, infer, def, body, child, inside_unsafe_block);
    });
 }
@@ -170,4 +181,25 @@ fn main() {
 "#,
        );
    }
+    #[test]
+    fn missing_unsafe_diagnostic_with_static_mut() {
+        check_diagnostics(
+            r#"
+struct Ty {
+    a: u8,
+}
+static mut static_mut: Ty = Ty { a: 0 };
+fn main() {
+    let x = static_mut.a;
+          //^^^^^^^^^^ This operation is unsafe and requires an unsafe function or block
+    unsafe {
+        let x = static_mut.a;
+    }
+}
+"#,
+        );
+    }
 }
diff --git a/crates/ra_hir_ty/src/infer.rs b/crates/ra_hir_ty/src/infer.rs
index 28f32a0a4..3d12039a6 100644
--- a/crates/ra_hir_ty/src/infer.rs
+++ b/crates/ra_hir_ty/src/infer.rs
@@ -440,6 +440,12 @@ impl<'a> InferenceContext<'a> {
                let ty = self.insert_type_vars(ty.subst(&substs));
                forbid_unresolved_segments((ty, Some(strukt.into())), unresolved)
            }
+            TypeNs::AdtId(AdtId::UnionId(u)) => {
+                let substs = Ty::substs_from_path(&ctx, path, u.into(), true);
+                let ty = self.db.ty(u.into());
+                let ty = self.insert_type_vars(ty.subst(&substs));
+                forbid_unresolved_segments((ty, Some(u.into())), unresolved)
+            }
            TypeNs::EnumVariantId(var) => {
                let substs = Ty::substs_from_path(&ctx, path, var.into(), true);
                let ty = self.db.ty(var.parent.into());
@@ -490,10 +496,7 @@ impl<'a> InferenceContext<'a> {
                // FIXME potentially resolve assoc type
                (Ty::Unknown, None)
            }
-            TypeNs::AdtId(AdtId::EnumId(_))
+            TypeNs::AdtId(AdtId::EnumId(_)) | TypeNs::BuiltinType(_) | TypeNs::TraitId(_) => {
-            | TypeNs::AdtId(AdtId::UnionId(_))
-            | TypeNs::BuiltinType(_)
-            | TypeNs::TraitId(_) => {
                // FIXME diagnostic
                (Ty::Unknown, None)
            }
diff --git a/crates/ra_hir_ty/src/lower.rs b/crates/ra_hir_ty/src/lower.rs
index 1eacc6f95..7638f167b 100644
--- a/crates/ra_hir_ty/src/lower.rs
+++ b/crates/ra_hir_ty/src/lower.rs
@@ -518,6 +518,7 @@ impl Ty {
        let (segment, generic_def) = match resolved {
            ValueTyDefId::FunctionId(it) => (last, Some(it.into())),
            ValueTyDefId::StructId(it) => (last, Some(it.into())),
+            ValueTyDefId::UnionId(it) => (last, Some(it.into())),
            ValueTyDefId::ConstId(it) => (last, Some(it.into())),
            ValueTyDefId::StaticId(_) => (last, None),
            ValueTyDefId::EnumVariantId(var) => {
@@ -1148,11 +1149,12 @@ impl_from!(BuiltinType, AdtId(StructId, EnumId, UnionId), TypeAliasId for TyDefI
 pub enum ValueTyDefId {
    FunctionId(FunctionId),
    StructId(StructId),
+    UnionId(UnionId),
    EnumVariantId(EnumVariantId),
    ConstId(ConstId),
    StaticId(StaticId),
 }
-impl_from!(FunctionId, StructId, EnumVariantId, ConstId, StaticId for ValueTyDefId);
+impl_from!(FunctionId, StructId, UnionId, EnumVariantId, ConstId, StaticId for ValueTyDefId);
 /// Build the declared type of an item. This depends on the namespace; e.g. for
 /// `struct Foo(usize)`, we have two types: The type of the struct itself, and
@@ -1179,6 +1181,7 @@ pub(crate) fn value_ty_query(db: &dyn HirDatabase, def: ValueTyDefId) -> Binders
    match def {
        ValueTyDefId::FunctionId(it) => type_for_fn(db, it),
        ValueTyDefId::StructId(it) => type_for_struct_constructor(db, it),
+        ValueTyDefId::UnionId(it) => type_for_adt(db, it.into()),
        ValueTyDefId::EnumVariantId(it) => type_for_enum_variant_constructor(db, it),
        ValueTyDefId::ConstId(it) => type_for_const(db, it),
        ValueTyDefId::StaticId(it) => type_for_static(db, it),
diff --git a/crates/ra_hir_ty/src/tests/simple.rs b/crates/ra_hir_ty/src/tests/simple.rs
index 3fd7d5cd4..5a7cf9455 100644
--- a/crates/ra_hir_ty/src/tests/simple.rs
+++ b/crates/ra_hir_ty/src/tests/simple.rs
@@ -334,16 +334,44 @@ fn infer_union() {
            bar: f32,
        }
+        fn test() {
+            let u = MyUnion { foo: 0 };
+            unsafe { baz(u); }
+            let u = MyUnion { bar: 0.0 };
+            unsafe { baz(u); }
+        }
        unsafe fn baz(u: MyUnion) {
            let inner = u.foo;
+            let inner = u.bar;
        }
        "#,
        expect![[r#"
-            61..62 'u': MyUnion
+            57..172 '{     ...); } }': ()
-            73..99 '{     ...foo; }': ()
+            67..68 'u': MyUnion
-            83..88 'inner': u32
+            71..89 'MyUnio...o: 0 }': MyUnion
-            91..92 'u': MyUnion
+            86..87 '0': u32
-            91..96 'u.foo': u32
+            95..113 'unsafe...(u); }': ()
+            102..113 '{ baz(u); }': ()
+            104..107 'baz': fn baz(MyUnion)
+            104..110 'baz(u)': ()
+            108..109 'u': MyUnion
+            122..123 'u': MyUnion
+            126..146 'MyUnio... 0.0 }': MyUnion
+            141..144 '0.0': f32
+            152..170 'unsafe...(u); }': ()
+            159..170 '{ baz(u); }': ()
+            161..164 'baz': fn baz(MyUnion)
+            161..167 'baz(u)': ()
+            165..166 'u': MyUnion
+            188..189 'u': MyUnion
+            200..249 '{     ...bar; }': ()
+            210..215 'inner': u32
+            218..219 'u': MyUnion
+            218..223 'u.foo': u32
+            233..238 'inner': f32
+            241..242 'u': MyUnion
+            241..246 'u.bar': f32
        "#]],
    );
 }
diff --git a/crates/ra_ide/src/completion/complete_snippet.rs b/crates/ra_ide/src/completion/complete_snippet.rs
index 28d8f7876..4368e4eec 100644
--- a/crates/ra_ide/src/completion/complete_snippet.rs
+++ b/crates/ra_ide/src/completion/complete_snippet.rs
@@ -36,7 +36,7 @@ pub(super) fn complete_item_snippet(acc: &mut Completions, ctx: &CompletionConte
    snippet(
        ctx,
        cap,
-        "Test module",
+        "tmod (Test module)",
        "\
 #[cfg(test)]
 mod tests {
@@ -54,7 +54,7 @@ mod tests {
    snippet(
        ctx,
        cap,
-        "Test function",
+        "tfn (Test function)",
        "\
 #[test]
 fn ${1:feature}() {
@@ -106,10 +106,10 @@ mod tests {
 }
 "#,
            expect![[r#"
-                sn Test function
-                sn Test module
                sn macro_rules
                sn pub(crate)
+                sn tfn (Test function)
+                sn tmod (Test module)
            "#]],
        )
    }
diff --git a/crates/ra_ide/src/completion/completion_context.rs b/crates/ra_ide/src/completion/completion_context.rs
index 6b03b30bb..4aa761148 100644
--- a/crates/ra_ide/src/completion/completion_context.rs
+++ b/crates/ra_ide/src/completion/completion_context.rs
@@ -27,7 +27,7 @@ pub(crate) struct CompletionContext<'a> {
    pub(super) scope: SemanticsScope<'a>,
    pub(super) db: &'a RootDatabase,
    pub(super) config: &'a CompletionConfig,
-    pub(super) offset: TextSize,
+    pub(super) position: FilePosition,
    /// The token before the cursor, in the original file.
    pub(super) original_token: SyntaxToken,
    /// The token before the cursor, in the macro-expanded file.
@@ -117,7 +117,7 @@ impl<'a> CompletionContext<'a> {
            config,
            original_token,
            token,
-            offset: position.offset,
+            position,
            krate,
            expected_type: None,
            name_ref_syntax: None,
@@ -209,7 +209,7 @@ impl<'a> CompletionContext<'a> {
            mark::hit!(completes_if_prefix_is_keyword);
            self.original_token.text_range()
        } else {
-            TextRange::empty(self.offset)
+            TextRange::empty(self.position.offset)
        }
    }
@@ -379,8 +379,8 @@ impl<'a> CompletionContext<'a> {
            self.is_path_type = path.syntax().parent().and_then(ast::PathType::cast).is_some();
            self.has_type_args = segment.generic_arg_list().is_some();
-            #[allow(deprecated)]
+            let hygiene = hir::Hygiene::new(self.db, self.position.file_id.into());
-            if let Some(path) = hir::Path::from_ast(path.clone()) {
+            if let Some(path) = hir::Path::from_src(path.clone(), &hygiene) {
                if let Some(path_prefix) = path.qualifier() {
                    self.path_prefix = Some(path_prefix);
                    return;
diff --git a/crates/ra_ide/src/completion/presentation.rs b/crates/ra_ide/src/completion/presentation.rs
index 9a94ff476..59f1b1424 100644
--- a/crates/ra_ide/src/completion/presentation.rs
+++ b/crates/ra_ide/src/completion/presentation.rs
@@ -2,8 +2,8 @@
 //! It also handles scoring (sorting) completions.
 use hir::{Docs, HasAttrs, HasSource, HirDisplay, ModPath, ScopeDef, StructKind, Type};
+use itertools::Itertools;
 use ra_syntax::ast::NameOwner;
-use stdx::SepBy;
 use test_utils::mark;
 use crate::{
@@ -289,16 +289,16 @@ impl Completions {
            .map(|field| (field.name(ctx.db), field.signature_ty(ctx.db)));
        let variant_kind = variant.kind(ctx.db);
        let detail = match variant_kind {
-            StructKind::Tuple | StructKind::Unit => detail_types
+            StructKind::Tuple | StructKind::Unit => format!(
-                .map(|(_, t)| t.display(ctx.db).to_string())
+                "({})",
-                .sep_by(", ")
+                detail_types.map(|(_, t)| t.display(ctx.db).to_string()).format(", ")
-                .surround_with("(", ")")
+            ),
-                .to_string(),
+            StructKind::Record => format!(
-            StructKind::Record => detail_types
+                "{{ {} }}",
-                .map(|(n, t)| format!("{}: {}", n, t.display(ctx.db).to_string()))
+                detail_types
-                .sep_by(", ")
+                    .map(|(n, t)| format!("{}: {}", n, t.display(ctx.db).to_string()))
-                .surround_with("{ ", " }")
+                    .format(", ")
-                .to_string(),
+            ),
        };
        let mut res = CompletionItem::new(
            CompletionKind::Reference,
@@ -412,11 +412,10 @@ impl Builder {
            self = self.trigger_call_info();
            let snippet = match (ctx.config.add_call_argument_snippets, params) {
                (true, Params::Named(params)) => {
-                    let function_params_snippet = params
+                    let function_params_snippet =
-                        .iter()
+                        params.iter().enumerate().format_with(", ", |(index, param_name), f| {
-                        .enumerate()
+                            f(&format_args!("${{{}:{}}}", index + 1, param_name))
-                        .map(|(index, param_name)| format!("${{{}:{}}}", index + 1, param_name))
+                        });
-                        .sep_by(", ");
                    format!("{}({})$0", name, function_params_snippet)
                }
                _ => {
diff --git a/crates/ra_ide/src/diagnostics.rs b/crates/ra_ide/src/diagnostics.rs
index 5ce900bf4..79dbb0865 100644
--- a/crates/ra_ide/src/diagnostics.rs
+++ b/crates/ra_ide/src/diagnostics.rs
@@ -6,22 +6,21 @@
 use std::cell::RefCell;
-use hir::{
+use hir::{diagnostics::DiagnosticSinkBuilder, Semantics};
-    diagnostics::{AstDiagnostic, Diagnostic as _, DiagnosticSinkBuilder},
-    HasSource, HirDisplay, Semantics, VariantDef,
-};
 use itertools::Itertools;
 use ra_db::SourceDatabase;
 use ra_ide_db::RootDatabase;
 use ra_prof::profile;
 use ra_syntax::{
-    algo,
+    ast::{self, AstNode},
-    ast::{self, edit::IndentLevel, make, AstNode},
    SyntaxNode, TextRange, T,
 };
 use ra_text_edit::{TextEdit, TextEditBuilder};
-use crate::{AnalysisConfig, Diagnostic, FileId, FileSystemEdit, Fix, SourceFileEdit};
+use crate::{AnalysisConfig, Diagnostic, FileId, Fix, SourceFileEdit};
+mod diagnostics_with_fix;
+use diagnostics_with_fix::DiagnosticWithFix;
 #[derive(Debug, Copy, Clone)]
 pub enum Severity {
@@ -56,77 +55,16 @@ pub(crate) fn diagnostics(
    let res = RefCell::new(res);
    let mut sink_builder = DiagnosticSinkBuilder::new()
        .on::<hir::diagnostics::UnresolvedModule, _>(|d| {
-            let original_file = d.source().file_id.original_file(db);
+            res.borrow_mut().push(diagnostic_with_fix(d, &sema));
-            let fix = Fix::new(
-                "Create module",
-                FileSystemEdit::CreateFile { anchor: original_file, dst: d.candidate.clone() }
-                    .into(),
-            );
-            res.borrow_mut().push(Diagnostic {
-                name: Some(d.name().into()),
-                range: sema.diagnostics_range(d).range,
-                message: d.message(),
-                severity: Severity::Error,
-                fix: Some(fix),
-            })
        })
        .on::<hir::diagnostics::MissingFields, _>(|d| {
-            // Note that although we could add a diagnostics to
+            res.borrow_mut().push(diagnostic_with_fix(d, &sema));
-            // fill the missing tuple field, e.g :
-            // `struct A(usize);`
-            // `let a = A { 0: () }`
-            // but it is uncommon usage and it should not be encouraged.
-            let fix = if d.missed_fields.iter().any(|it| it.as_tuple_index().is_some()) {
-                None
-            } else {
-                let mut field_list = d.ast(db);
-                for f in d.missed_fields.iter() {
-                    let field = make::record_expr_field(
-                        make::name_ref(&f.to_string()),
-                        Some(make::expr_unit()),
-                    );
-                    field_list = field_list.append_field(&field);
-                }
-                let edit = {
-                    let mut builder = TextEditBuilder::default();
-                    algo::diff(&d.ast(db).syntax(), &field_list.syntax())
-                        .into_text_edit(&mut builder);
-                    builder.finish()
-                };
-                Some(Fix::new("Fill struct fields", SourceFileEdit { file_id, edit }.into()))
-            };
-            res.borrow_mut().push(Diagnostic {
-                name: Some(d.name().into()),
-                range: sema.diagnostics_range(d).range,
-                message: d.message(),
-                severity: Severity::Error,
-                fix,
-            })
        })
        .on::<hir::diagnostics::MissingOkInTailExpr, _>(|d| {
-            let node = d.ast(db);
+            res.borrow_mut().push(diagnostic_with_fix(d, &sema));
-            let replacement = format!("Ok({})", node.syntax());
-            let edit = TextEdit::replace(node.syntax().text_range(), replacement);
-            let source_change = SourceFileEdit { file_id, edit }.into();
-            let fix = Fix::new("Wrap with ok", source_change);
-            res.borrow_mut().push(Diagnostic {
-                name: Some(d.name().into()),
-                range: sema.diagnostics_range(d).range,
-                message: d.message(),
-                severity: Severity::Error,
-                fix: Some(fix),
-            })
        })
        .on::<hir::diagnostics::NoSuchField, _>(|d| {
-            res.borrow_mut().push(Diagnostic {
+            res.borrow_mut().push(diagnostic_with_fix(d, &sema));
-                name: Some(d.name().into()),
-                range: sema.diagnostics_range(d).range,
-                message: d.message(),
-                severity: Severity::Error,
-                fix: missing_struct_field_fix(&sema, file_id, d),
-            })
        })
        // Only collect experimental diagnostics when they're enabled.
        .filter(|diag| !diag.is_experimental() || enable_experimental);
@@ -144,7 +82,7 @@ pub(crate) fn diagnostics(
            res.borrow_mut().push(Diagnostic {
                name: Some(d.name().into()),
                message: d.message(),
-                range: sema.diagnostics_range(d).range,
+                range: sema.diagnostics_display_range(d).range,
                severity: Severity::Error,
                fix: None,
            })
@@ -157,77 +95,13 @@ pub(crate) fn diagnostics(
    res.into_inner()
 }
-fn missing_struct_field_fix(
+fn diagnostic_with_fix<D: DiagnosticWithFix>(d: &D, sema: &Semantics<RootDatabase>) -> Diagnostic {
-    sema: &Semantics<RootDatabase>,
+    Diagnostic {
-    usage_file_id: FileId,
+        name: Some(d.name().into()),
-    d: &hir::diagnostics::NoSuchField,
+        range: sema.diagnostics_display_range(d).range,
-) -> Option<Fix> {
+        message: d.message(),
-    let record_expr = sema.ast(d);
+        severity: Severity::Error,
+        fix: d.fix(&sema),
-    let record_lit = ast::RecordExpr::cast(record_expr.syntax().parent()?.parent()?)?;
-    let def_id = sema.resolve_variant(record_lit)?;
-    let module;
-    let def_file_id;
-    let record_fields = match VariantDef::from(def_id) {
-        VariantDef::Struct(s) => {
-            module = s.module(sema.db);
-            let source = s.source(sema.db);
-            def_file_id = source.file_id;
-            let fields = source.value.field_list()?;
-            record_field_list(fields)?
-        }
-        VariantDef::Union(u) => {
-            module = u.module(sema.db);
-            let source = u.source(sema.db);
-            def_file_id = source.file_id;
-            source.value.record_field_list()?
-        }
-        VariantDef::EnumVariant(e) => {
-            module = e.module(sema.db);
-            let source = e.source(sema.db);
-            def_file_id = source.file_id;
-            let fields = source.value.field_list()?;
-            record_field_list(fields)?
-        }
-    };
-    let def_file_id = def_file_id.original_file(sema.db);
-    let new_field_type = sema.type_of_expr(&record_expr.expr()?)?;
-    if new_field_type.is_unknown() {
-        return None;
-    }
-    let new_field = make::record_field(
-        record_expr.field_name()?,
-        make::ty(&new_field_type.display_source_code(sema.db, module.into()).ok()?),
-    );
-    let last_field = record_fields.fields().last()?;
-    let last_field_syntax = last_field.syntax();
-    let indent = IndentLevel::from_node(last_field_syntax);
-    let mut new_field = new_field.to_string();
-    if usage_file_id != def_file_id {
-        new_field = format!("pub(crate) {}", new_field);
-    }
-    new_field = format!("\n{}{}", indent, new_field);
-    let needs_comma = !last_field_syntax.to_string().ends_with(',');
-    if needs_comma {
-        new_field = format!(",{}", new_field);
-    }
-    let source_change = SourceFileEdit {
-        file_id: def_file_id,
-        edit: TextEdit::insert(last_field_syntax.text_range().end(), new_field),
-    };
-    let fix = Fix::new("Create field", source_change.into());
-    return Some(fix);
-    fn record_field_list(field_def_list: ast::FieldList) -> Option<ast::RecordFieldList> {
-        match field_def_list {
-            ast::FieldList::RecordFieldList(it) => Some(it),
-            ast::FieldList::TupleFieldList(_) => None,
-        }
    }
 }
@@ -238,25 +112,26 @@ fn check_unnecessary_braces_in_use_statement(
 ) -> Option<()> {
    let use_tree_list = ast::UseTreeList::cast(node.clone())?;
    if let Some((single_use_tree,)) = use_tree_list.use_trees().collect_tuple() {
-        let range = use_tree_list.syntax().text_range();
+        let use_range = use_tree_list.syntax().text_range();
        let edit =
            text_edit_for_remove_unnecessary_braces_with_self_in_use_statement(&single_use_tree)
                .unwrap_or_else(|| {
                    let to_replace = single_use_tree.syntax().text().to_string();
                    let mut edit_builder = TextEditBuilder::default();
-                    edit_builder.delete(range);
+                    edit_builder.delete(use_range);
-                    edit_builder.insert(range.start(), to_replace);
+                    edit_builder.insert(use_range.start(), to_replace);
                    edit_builder.finish()
                });
        acc.push(Diagnostic {
            name: None,
-            range,
+            range: use_range,
            message: "Unnecessary braces in use statement".to_string(),
            severity: Severity::WeakWarning,
            fix: Some(Fix::new(
                "Remove unnecessary braces",
                SourceFileEdit { file_id, edit }.into(),
+                use_range,
            )),
        });
    }
@@ -271,8 +146,7 @@ fn text_edit_for_remove_unnecessary_braces_with_self_in_use_statement(
    if single_use_tree.path()?.segment()?.syntax().first_child_or_token()?.kind() == T![self] {
        let start = use_tree_list_node.prev_sibling_or_token()?.text_range().start();
        let end = use_tree_list_node.text_range().end();
-        let range = TextRange::new(start, end);
+        return Some(TextEdit::delete(TextRange::new(start, end)));
-        return Some(TextEdit::delete(range));
    }
    None
 }
@@ -295,14 +169,16 @@ fn check_struct_shorthand_initialization(
                edit_builder.insert(record_field.syntax().text_range().start(), field_name);
                let edit = edit_builder.finish();
+                let field_range = record_field.syntax().text_range();
                acc.push(Diagnostic {
                    name: None,
-                    range: record_field.syntax().text_range(),
+                    range: field_range,
                    message: "Shorthand struct initialization".to_string(),
                    severity: Severity::WeakWarning,
                    fix: Some(Fix::new(
                        "Use struct shorthand initialization",
                        SourceFileEdit { file_id, edit }.into(),
+                        field_range,
                    )),
                });
            }
@@ -326,7 +202,7 @@ mod tests {
    /// Takes a multi-file input fixture with annotated cursor positions,
    /// and checks that:
    ///  * a diagnostic is produced
-    ///  * this diagnostic touches the input cursor position
+    ///  * this diagnostic fix trigger range touches the input cursor position
    ///  * that the contents of the file containing the cursor match `after` after the diagnostic fix is applied
    fn check_fix(ra_fixture_before: &str, ra_fixture_after: &str) {
        let after = trim_indent(ra_fixture_after);
@@ -344,10 +220,10 @@ mod tests {
        assert_eq_text!(&after, &actual);
        assert!(
-            diagnostic.range.start() <= file_position.offset
+            fix.fix_trigger_range.start() <= file_position.offset
-                && diagnostic.range.end() >= file_position.offset,
+                && fix.fix_trigger_range.end() >= file_position.offset,
-            "diagnostic range {:?} does not touch cursor position {:?}",
+            "diagnostic fix range {:?} does not touch cursor position {:?}",
-            diagnostic.range,
+            fix.fix_trigger_range,
            file_position.offset
        );
    }
@@ -712,6 +588,7 @@ fn test_fn() {
                                    ],
                                    is_snippet: false,
                                },
+                                fix_trigger_range: 0..8,
                            },
                        ),
                    },
diff --git a/crates/ra_ide/src/diagnostics/diagnostics_with_fix.rs b/crates/ra_ide/src/diagnostics/diagnostics_with_fix.rs
new file mode 100644
index 000000000..f7c73773f
--- /dev/null
+++ b/crates/ra_ide/src/diagnostics/diagnostics_with_fix.rs
@@ -0,0 +1,171 @@
+//! Provides a way to attach fixes to the diagnostics.
+//! The same module also has all curret custom fixes for the diagnostics implemented.
+use crate::Fix;
+use ast::{edit::IndentLevel, make};
+use hir::{
+    db::AstDatabase,
+    diagnostics::{Diagnostic, MissingFields, MissingOkInTailExpr, NoSuchField, UnresolvedModule},
+    HasSource, HirDisplay, Semantics, VariantDef,
+};
+use ra_db::FileId;
+use ra_ide_db::{
+    source_change::{FileSystemEdit, SourceFileEdit},
+    RootDatabase,
+};
+use ra_syntax::{algo, ast, AstNode};
+use ra_text_edit::{TextEdit, TextEditBuilder};
+/// A [Diagnostic] that potentially has a fix available.
+///
+/// [Diagnostic]: hir::diagnostics::Diagnostic
+pub trait DiagnosticWithFix: Diagnostic {
+    fn fix(&self, sema: &Semantics<RootDatabase>) -> Option<Fix>;
+}
+impl DiagnosticWithFix for UnresolvedModule {
+    fn fix(&self, sema: &Semantics<RootDatabase>) -> Option<Fix> {
+        let root = sema.db.parse_or_expand(self.file)?;
+        let unresolved_module = self.decl.to_node(&root);
+        Some(Fix::new(
+            "Create module",
+            FileSystemEdit::CreateFile {
+                anchor: self.file.original_file(sema.db),
+                dst: self.candidate.clone(),
+            }
+            .into(),
+            unresolved_module.syntax().text_range(),
+        ))
+    }
+}
+impl DiagnosticWithFix for NoSuchField {
+    fn fix(&self, sema: &Semantics<RootDatabase>) -> Option<Fix> {
+        let root = sema.db.parse_or_expand(self.file)?;
+        missing_record_expr_field_fix(
+            &sema,
+            self.file.original_file(sema.db),
+            &self.field.to_node(&root),
+        )
+    }
+}
+impl DiagnosticWithFix for MissingFields {
+    fn fix(&self, sema: &Semantics<RootDatabase>) -> Option<Fix> {
+        // Note that although we could add a diagnostics to
+        // fill the missing tuple field, e.g :
+        // `struct A(usize);`
+        // `let a = A { 0: () }`
+        // but it is uncommon usage and it should not be encouraged.
+        if self.missed_fields.iter().any(|it| it.as_tuple_index().is_some()) {
+            return None;
+        }
+        let root = sema.db.parse_or_expand(self.file)?;
+        let old_field_list = self.field_list_parent.to_node(&root).record_expr_field_list()?;
+        let mut new_field_list = old_field_list.clone();
+        for f in self.missed_fields.iter() {
+            let field =
+                make::record_expr_field(make::name_ref(&f.to_string()), Some(make::expr_unit()));
+            new_field_list = new_field_list.append_field(&field);
+        }
+        let edit = {
+            let mut builder = TextEditBuilder::default();
+            algo::diff(&old_field_list.syntax(), &new_field_list.syntax())
+                .into_text_edit(&mut builder);
+            builder.finish()
+        };
+        Some(Fix::new(
+            "Fill struct fields",
+            SourceFileEdit { file_id: self.file.original_file(sema.db), edit }.into(),
+            sema.original_range(&old_field_list.syntax()).range,
+        ))
+    }
+}
+impl DiagnosticWithFix for MissingOkInTailExpr {
+    fn fix(&self, sema: &Semantics<RootDatabase>) -> Option<Fix> {
+        let root = sema.db.parse_or_expand(self.file)?;
+        let tail_expr = self.expr.to_node(&root);
+        let tail_expr_range = tail_expr.syntax().text_range();
+        let edit = TextEdit::replace(tail_expr_range, format!("Ok({})", tail_expr.syntax()));
+        let source_change =
+            SourceFileEdit { file_id: self.file.original_file(sema.db), edit }.into();
+        Some(Fix::new("Wrap with ok", source_change, tail_expr_range))
+    }
+}
+fn missing_record_expr_field_fix(
+    sema: &Semantics<RootDatabase>,
+    usage_file_id: FileId,
+    record_expr_field: &ast::RecordExprField,
+) -> Option<Fix> {
+    let record_lit = ast::RecordExpr::cast(record_expr_field.syntax().parent()?.parent()?)?;
+    let def_id = sema.resolve_variant(record_lit)?;
+    let module;
+    let def_file_id;
+    let record_fields = match VariantDef::from(def_id) {
+        VariantDef::Struct(s) => {
+            module = s.module(sema.db);
+            let source = s.source(sema.db);
+            def_file_id = source.file_id;
+            let fields = source.value.field_list()?;
+            record_field_list(fields)?
+        }
+        VariantDef::Union(u) => {
+            module = u.module(sema.db);
+            let source = u.source(sema.db);
+            def_file_id = source.file_id;
+            source.value.record_field_list()?
+        }
+        VariantDef::EnumVariant(e) => {
+            module = e.module(sema.db);
+            let source = e.source(sema.db);
+            def_file_id = source.file_id;
+            let fields = source.value.field_list()?;
+            record_field_list(fields)?
+        }
+    };
+    let def_file_id = def_file_id.original_file(sema.db);
+    let new_field_type = sema.type_of_expr(&record_expr_field.expr()?)?;
+    if new_field_type.is_unknown() {
+        return None;
+    }
+    let new_field = make::record_field(
+        record_expr_field.field_name()?,
+        make::ty(&new_field_type.display_source_code(sema.db, module.into()).ok()?),
+    );
+    let last_field = record_fields.fields().last()?;
+    let last_field_syntax = last_field.syntax();
+    let indent = IndentLevel::from_node(last_field_syntax);
+    let mut new_field = new_field.to_string();
+    if usage_file_id != def_file_id {
+        new_field = format!("pub(crate) {}", new_field);
+    }
+    new_field = format!("\n{}{}", indent, new_field);
+    let needs_comma = !last_field_syntax.to_string().ends_with(',');
+    if needs_comma {
+        new_field = format!(",{}", new_field);
+    }
+    let source_change = SourceFileEdit {
+        file_id: def_file_id,
+        edit: TextEdit::insert(last_field_syntax.text_range().end(), new_field),
+    };
+    return Some(Fix::new(
+        "Create field",
+        source_change.into(),
+        record_expr_field.syntax().text_range(),
+    ));
+    fn record_field_list(field_def_list: ast::FieldList) -> Option<ast::RecordFieldList> {
+        match field_def_list {
+            ast::FieldList::RecordFieldList(it) => Some(it),
+            ast::FieldList::TupleFieldList(_) => None,
+        }
+    }
+}
diff --git a/crates/ra_ide/src/display/short_label.rs b/crates/ra_ide/src/display/short_label.rs
index 0fdf8e9a5..010c34705 100644
--- a/crates/ra_ide/src/display/short_label.rs
+++ b/crates/ra_ide/src/display/short_label.rs
@@ -47,6 +47,12 @@ impl ShortLabel for ast::Module {
    }
 }
+impl ShortLabel for ast::SourceFile {
+    fn short_label(&self) -> Option<String> {
+        None
+    }
+}
 impl ShortLabel for ast::TypeAlias {
    fn short_label(&self) -> Option<String> {
        short_label_from_node(self, "type ")
@@ -55,7 +61,11 @@ impl ShortLabel for ast::TypeAlias {
 impl ShortLabel for ast::Const {
    fn short_label(&self) -> Option<String> {
-        short_label_from_ty(self, self.ty(), "const ")
+        let mut new_buf = short_label_from_ty(self, self.ty(), "const ")?;
+        if let Some(expr) = self.body() {
+            format_to!(new_buf, " = {}", expr.syntax());
+        }
+        Some(new_buf)
    }
 }
diff --git a/crates/ra_ide/src/goto_definition.rs b/crates/ra_ide/src/goto_definition.rs
index 4e3f428fa..45389fd23 100644
--- a/crates/ra_ide/src/goto_definition.rs
+++ b/crates/ra_ide/src/goto_definition.rs
@@ -1,6 +1,6 @@
 use hir::Semantics;
 use ra_ide_db::{
-    defs::{classify_name, classify_name_ref, NameClass},
+    defs::{classify_name, classify_name_ref},
    symbol_index, RootDatabase,
 };
 use ra_syntax::{
@@ -40,10 +40,7 @@ pub(crate) fn goto_definition(
                reference_definition(&sema, &name_ref).to_vec()
            },
            ast::Name(name) => {
-                let def = match classify_name(&sema, &name)? {
+                let def = classify_name(&sema, &name)?.definition(sema.db);
-                    NameClass::Definition(def) | NameClass::ConstReference(def) => def,
-                    NameClass::FieldShorthand { local: _, field } => field,
-                };
                let nav = def.try_to_nav(sema.db)?;
                vec![nav]
            },
@@ -86,8 +83,7 @@ pub(crate) fn reference_definition(
 ) -> ReferenceResult {
    let name_kind = classify_name_ref(sema, name_ref);
    if let Some(def) = name_kind {
-        let def = def.definition();
+        let def = def.definition(sema.db);
        return match def.try_to_nav(sema.db) {
            Some(nav) => ReferenceResult::Exact(nav),
            None => ReferenceResult::Approximate(Vec::new()),
@@ -134,6 +130,32 @@ mod tests {
    }
    #[test]
+    fn goto_def_for_extern_crate() {
+        check(
+            r#"
+            //- /main.rs
+            extern crate std<|>;
+            //- /std/lib.rs
+            // empty
+            //^ file
+            "#,
+        )
+    }
+    #[test]
+    fn goto_def_for_renamed_extern_crate() {
+        check(
+            r#"
+            //- /main.rs
+            extern crate std as abc<|>;
+            //- /std/lib.rs
+            // empty
+            //^ file
+            "#,
+        )
+    }
+    #[test]
    fn goto_def_in_items() {
        check(
            r#"
diff --git a/crates/ra_ide/src/hover.rs b/crates/ra_ide/src/hover.rs
index aa48cb412..f66f62bfb 100644
--- a/crates/ra_ide/src/hover.rs
+++ b/crates/ra_ide/src/hover.rs
@@ -85,8 +85,8 @@ pub(crate) fn hover(db: &RootDatabase, position: FilePosition) -> Option<RangeIn
    let node = token.parent();
    let definition = match_ast! {
        match node {
-            ast::NameRef(name_ref) => classify_name_ref(&sema, &name_ref).map(|d| d.definition()),
+            ast::NameRef(name_ref) => classify_name_ref(&sema, &name_ref).map(|d| d.definition(sema.db)),
-            ast::Name(name) => classify_name(&sema, &name).map(|d| d.definition()),
+            ast::Name(name) => classify_name(&sema, &name).map(|d| d.definition(sema.db)),
            _ => None,
        }
    };
@@ -304,7 +304,10 @@ fn hover_for_definition(db: &RootDatabase, def: Definition) -> Option<Markup> {
                    let docs = Documentation::from_ast(&it).map(Into::into);
                    hover_markup(docs, it.short_label(), mod_path)
                }
-                _ => None,
+                ModuleSource::SourceFile(it) => {
+                    let docs = Documentation::from_ast(&it).map(Into::into);
+                    hover_markup(docs, it.short_label(), mod_path)
+                }
            },
            ModuleDef::Function(it) => from_def_source(db, it, mod_path),
            ModuleDef::Adt(Adt::Struct(it)) => from_def_source(db, it, mod_path),
@@ -509,6 +512,37 @@ fn main() { }
    }
    #[test]
+    fn hover_shows_fn_doc() {
+        check(
+            r#"
+/// # Example
+/// ```
+/// # use std::path::Path;
+/// #
+/// foo(Path::new("hello, world!"))
+/// ```
+pub fn foo<|>(_: &Path) {}
+fn main() { }
+"#,
+            expect![[r#"
+                *foo*
+                ```rust
+                pub fn foo(_: &Path)
+                ```
+                ___
+                # Example
+                ```
+                # use std::path::Path;
+                #
+                foo(Path::new("hello, world!"))
+                ```
+            "#]],
+        );
+    }
+    #[test]
    fn hover_shows_struct_field_info() {
        // Hovering over the field when instantiating
        check(
@@ -556,16 +590,16 @@ fn main() {
    #[test]
    fn hover_const_static() {
        check(
-            r#"const foo<|>: u32 = 0;"#,
+            r#"const foo<|>: u32 = 123;"#,
            expect![[r#"
                *foo*
                ```rust
-                const foo: u32
+                const foo: u32 = 123
                ```
            "#]],
        );
        check(
-            r#"static foo<|>: u32 = 0;"#,
+            r#"static foo<|>: u32 = 456;"#,
            expect![[r#"
                *foo*
                ```rust
@@ -800,7 +834,7 @@ fn main() {
            expect![[r#"
                *C*
                ```rust
-                const C: u32
+                const C: u32 = 1
                ```
            "#]],
        )
@@ -1107,6 +1141,46 @@ fn bar() { fo<|>o(); }
    }
    #[test]
+    fn test_hover_extern_crate() {
+        check(
+            r#"
+//- /main.rs
+extern crate st<|>d;
+//- /std/lib.rs
+//! Standard library for this test
+//!
+//! Printed?
+//! abc123
+            "#,
+            expect![[r#"
+            *std*
+            Standard library for this test
+            Printed?
+            abc123
+            "#]],
+        );
+        check(
+            r#"
+//- /main.rs
+extern crate std as ab<|>c;
+//- /std/lib.rs
+//! Standard library for this test
+//!
+//! Printed?
+//! abc123
+            "#,
+            expect![[r#"
+            *abc*
+            Standard library for this test
+            Printed?
+            abc123
+            "#]],
+        );
+    }
+    #[test]
    fn test_hover_mod_with_same_name_as_function() {
        check(
            r#"
diff --git a/crates/ra_ide/src/lib.rs b/crates/ra_ide/src/lib.rs
index 3822b9409..2cbd7e4f0 100644
--- a/crates/ra_ide/src/lib.rs
+++ b/crates/ra_ide/src/lib.rs
@@ -119,13 +119,19 @@ pub struct Diagnostic {
 pub struct Fix {
    pub label: String,
    pub source_change: SourceChange,
+    /// Allows to trigger the fix only when the caret is in the range given
+    pub fix_trigger_range: TextRange,
 }
 impl Fix {
-    pub fn new(label: impl Into<String>, source_change: SourceChange) -> Self {
+    pub fn new(
+        label: impl Into<String>,
+        source_change: SourceChange,
+        fix_trigger_range: TextRange,
+    ) -> Self {
        let label = label.into();
        assert!(label.starts_with(char::is_uppercase) && !label.ends_with('.'));
-        Self { label, source_change }
+        Self { label, source_change, fix_trigger_range }
    }
 }
diff --git a/crates/ra_ide/src/references.rs b/crates/ra_ide/src/references.rs
index cf456630a..453985de3 100644
--- a/crates/ra_ide/src/references.rs
+++ b/crates/ra_ide/src/references.rs
@@ -130,13 +130,13 @@ fn find_name(
    opt_name: Option<ast::Name>,
 ) -> Option<RangeInfo<Definition>> {
    if let Some(name) = opt_name {
-        let def = classify_name(sema, &name)?.definition();
+        let def = classify_name(sema, &name)?.definition(sema.db);
        let range = name.syntax().text_range();
        return Some(RangeInfo::new(range, def));
    }
    let name_ref =
        sema.find_node_at_offset_with_descend::<ast::NameRef>(&syntax, position.offset)?;
-    let def = classify_name_ref(sema, &name_ref)?.definition();
+    let def = classify_name_ref(sema, &name_ref)?.definition(sema.db);
    let range = name_ref.syntax().text_range();
    Some(RangeInfo::new(range, def))
 }
diff --git a/crates/ra_ide/src/ssr.rs b/crates/ra_ide/src/ssr.rs
index 4348b43be..8be862fd6 100644
--- a/crates/ra_ide/src/ssr.rs
+++ b/crates/ra_ide/src/ssr.rs
@@ -21,8 +21,8 @@ use ra_ssr::{MatchFinder, SsrError, SsrRule};
 // replacement occurs. For example if our replacement template is `foo::Bar` and we match some
 // code in the `foo` module, we'll insert just `Bar`.
 //
-// Method calls should generally be written in UFCS form. e.g. `foo::Bar::baz($s, $a)` will match
+// Inherent method calls should generally be written in UFCS form. e.g. `foo::Bar::baz($s, $a)` will
-// `$s.baz($a)`, provided the method call `baz` resolves to the method `foo::Bar::baz`.
+// match `$s.baz($a)`, provided the method call `baz` resolves to the method `foo::Bar::baz`.
 //
 // The scope of the search / replace will be restricted to the current selection if any, otherwise
 // it will apply to the whole workspace.
diff --git a/crates/ra_ide/src/syntax_highlighting.rs b/crates/ra_ide/src/syntax_highlighting.rs
index a32ae0165..c10e15db8 100644
--- a/crates/ra_ide/src/syntax_highlighting.rs
+++ b/crates/ra_ide/src/syntax_highlighting.rs
@@ -4,7 +4,7 @@ mod injection;
 #[cfg(test)]
 mod tests;
-use hir::{Name, Semantics};
+use hir::{Name, Semantics, VariantDef};
 use ra_ide_db::{
    defs::{classify_name, classify_name_ref, Definition, NameClass, NameRefClass},
    RootDatabase,
@@ -455,6 +455,18 @@ fn macro_call_range(macro_call: &ast::MacroCall) -> Option<TextRange> {
    Some(TextRange::new(range_start, range_end))
 }
+fn is_possibly_unsafe(name_ref: &ast::NameRef) -> bool {
+    name_ref
+        .syntax()
+        .parent()
+        .and_then(|parent| {
+            ast::FieldExpr::cast(parent.clone())
+                .map(|_| true)
+                .or_else(|| ast::RecordPatField::cast(parent).map(|_| true))
+        })
+        .unwrap_or(false)
+}
 fn highlight_element(
    sema: &Semantics<RootDatabase>,
    bindings_shadow_count: &mut FxHashMap<Name, u32>,
@@ -483,11 +495,21 @@ fn highlight_element(
            };
            match name_kind {
+                Some(NameClass::ExternCrate(_)) => HighlightTag::Module.into(),
                Some(NameClass::Definition(def)) => {
-                    highlight_name(db, def) | HighlightModifier::Definition
+                    highlight_name(sema, db, def, None, false) | HighlightModifier::Definition
+                }
+                Some(NameClass::ConstReference(def)) => highlight_name(sema, db, def, None, false),
+                Some(NameClass::FieldShorthand { field, .. }) => {
+                    let mut h = HighlightTag::Field.into();
+                    if let Definition::Field(field) = field {
+                        if let VariantDef::Union(_) = field.parent_def(db) {
+                            h |= HighlightModifier::Unsafe;
+                        }
+                    }
+                    h
                }
-                Some(NameClass::ConstReference(def)) => highlight_name(db, def),
-                Some(NameClass::FieldShorthand { .. }) => HighlightTag::Field.into(),
                None => highlight_name_by_syntax(name) | HighlightModifier::Definition,
            }
        }
@@ -498,8 +520,10 @@ fn highlight_element(
        }
        NAME_REF => {
            let name_ref = element.into_node().and_then(ast::NameRef::cast).unwrap();
+            let possibly_unsafe = is_possibly_unsafe(&name_ref);
            match classify_name_ref(sema, &name_ref) {
                Some(name_kind) => match name_kind {
+                    NameRefClass::ExternCrate(_) => HighlightTag::Module.into(),
                    NameRefClass::Definition(def) => {
                        if let Definition::Local(local) = &def {
                            if let Some(name) = local.name(db) {
@@ -508,11 +532,13 @@ fn highlight_element(
                                binding_hash = Some(calc_binding_hash(&name, *shadow_count))
                            }
                        };
-                        highlight_name(db, def)
+                        highlight_name(sema, db, def, Some(name_ref), possibly_unsafe)
                    }
                    NameRefClass::FieldShorthand { .. } => HighlightTag::Field.into(),
                },
-                None if syntactic_name_ref_highlighting => highlight_name_ref_by_syntax(name_ref),
+                None if syntactic_name_ref_highlighting => {
+                    highlight_name_ref_by_syntax(name_ref, sema)
+                }
                None => HighlightTag::UnresolvedReference.into(),
            }
        }
@@ -540,9 +566,20 @@ fn highlight_element(
            }
        }
        p if p.is_punct() => match p {
-            T![::] | T![->] | T![=>] | T![&] | T![..] | T![=] | T![@] => {
+            T![&] => {
-                HighlightTag::Operator.into()
+                let h = HighlightTag::Operator.into();
+                let is_unsafe = element
+                    .parent()
+                    .and_then(ast::RefExpr::cast)
+                    .map(|ref_expr| sema.is_unsafe_ref_expr(&ref_expr))
+                    .unwrap_or(false);
+                if is_unsafe {
+                    h | HighlightModifier::Unsafe
+                } else {
+                    h
+                }
            }
+            T![::] | T![->] | T![=>] | T![..] | T![=] | T![@] => HighlightTag::Operator.into(),
            T![!] if element.parent().and_then(ast::MacroCall::cast).is_some() => {
                HighlightTag::Macro.into()
            }
@@ -623,6 +660,18 @@ fn highlight_element(
                        HighlightTag::SelfKeyword.into()
                    }
                }
+                T![ref] => element
+                    .parent()
+                    .and_then(ast::IdentPat::cast)
+                    .and_then(|ident_pat| {
+                        if sema.is_unsafe_ident_pat(&ident_pat) {
+                            Some(HighlightModifier::Unsafe)
+                        } else {
+                            None
+                        }
+                    })
+                    .map(|modifier| h | modifier)
+                    .unwrap_or(h),
                _ => h,
            }
        }
@@ -652,16 +701,40 @@ fn is_child_of_impl(element: &SyntaxElement) -> bool {
    }
 }
-fn highlight_name(db: &RootDatabase, def: Definition) -> Highlight {
+fn highlight_name(
+    sema: &Semantics<RootDatabase>,
+    db: &RootDatabase,
+    def: Definition,
+    name_ref: Option<ast::NameRef>,
+    possibly_unsafe: bool,
+) -> Highlight {
    match def {
        Definition::Macro(_) => HighlightTag::Macro,
-        Definition::Field(_) => HighlightTag::Field,
+        Definition::Field(field) => {
+            let mut h = HighlightTag::Field.into();
+            if possibly_unsafe {
+                if let VariantDef::Union(_) = field.parent_def(db) {
+                    h |= HighlightModifier::Unsafe;
+                }
+            }
+            return h;
+        }
        Definition::ModuleDef(def) => match def {
            hir::ModuleDef::Module(_) => HighlightTag::Module,
            hir::ModuleDef::Function(func) => {
                let mut h = HighlightTag::Function.into();
                if func.is_unsafe(db) {
                    h |= HighlightModifier::Unsafe;
+                } else {
+                    let is_unsafe = name_ref
+                        .and_then(|name_ref| name_ref.syntax().parent())
+                        .and_then(ast::MethodCallExpr::cast)
+                        .map(|method_call_expr| sema.is_unsafe_method_call(method_call_expr))
+                        .unwrap_or(false);
+                    if is_unsafe {
+                        h |= HighlightModifier::Unsafe;
+                    }
                }
                return h;
            }
@@ -677,6 +750,7 @@ fn highlight_name(db: &RootDatabase, def: Definition) -> Highlight {
                let mut h = Highlight::new(HighlightTag::Static);
                if s.is_mut(db) {
                    h |= HighlightModifier::Mutable;
+                    h |= HighlightModifier::Unsafe;
                }
                return h;
            }
@@ -724,7 +798,7 @@ fn highlight_name_by_syntax(name: ast::Name) -> Highlight {
    tag.into()
 }
-fn highlight_name_ref_by_syntax(name: ast::NameRef) -> Highlight {
+fn highlight_name_ref_by_syntax(name: ast::NameRef, sema: &Semantics<RootDatabase>) -> Highlight {
    let default = HighlightTag::UnresolvedReference;
    let parent = match name.syntax().parent() {
@@ -732,9 +806,36 @@ fn highlight_name_ref_by_syntax(name: ast::NameRef) -> Highlight {
        _ => return default.into(),
    };
-    let tag = match parent.kind() {
+    match parent.kind() {
-        METHOD_CALL_EXPR => HighlightTag::Function,
+        METHOD_CALL_EXPR => {
-        FIELD_EXPR => HighlightTag::Field,
+            let mut h = Highlight::new(HighlightTag::Function);
+            let is_unsafe = ast::MethodCallExpr::cast(parent)
+                .map(|method_call_expr| sema.is_unsafe_method_call(method_call_expr))
+                .unwrap_or(false);
+            if is_unsafe {
+                h |= HighlightModifier::Unsafe;
+            }
+            h
+        }
+        FIELD_EXPR => {
+            let h = HighlightTag::Field;
+            let is_union = ast::FieldExpr::cast(parent)
+                .and_then(|field_expr| {
+                    let field = sema.resolve_field(&field_expr)?;
+                    Some(if let VariantDef::Union(_) = field.parent_def(sema.db) {
+                        true
+                    } else {
+                        false
+                    })
+                })
+                .unwrap_or(false);
+            if is_union {
+                h | HighlightModifier::Unsafe
+            } else {
+                h.into()
+            }
+        }
        PATH_SEGMENT => {
            let path = match parent.parent().and_then(ast::Path::cast) {
                Some(it) => it,
@@ -758,18 +859,15 @@ fn highlight_name_ref_by_syntax(name: ast::NameRef) -> Highlight {
            };
            match parent.kind() {
-                CALL_EXPR => HighlightTag::Function,
+                CALL_EXPR => HighlightTag::Function.into(),
-                _ => {
+                _ => if name.text().chars().next().unwrap_or_default().is_uppercase() {
-                    if name.text().chars().next().unwrap_or_default().is_uppercase() {
+                    HighlightTag::Struct.into()
-                        HighlightTag::Struct
+                } else {
-                    } else {
+                    HighlightTag::Constant
-                        HighlightTag::Constant
-                    }
                }
+                .into(),
            }
        }
-        _ => default,
+        _ => default.into(),
-    };
+    }
-    tag.into()
 }
diff --git a/crates/ra_ide/src/syntax_highlighting/injection.rs b/crates/ra_ide/src/syntax_highlighting/injection.rs
index 8665b480f..6046643ef 100644
--- a/crates/ra_ide/src/syntax_highlighting/injection.rs
+++ b/crates/ra_ide/src/syntax_highlighting/injection.rs
@@ -4,8 +4,8 @@ use std::{collections::BTreeMap, convert::TryFrom};
 use ast::{HasQuotes, HasStringValue};
 use hir::Semantics;
+use itertools::Itertools;
 use ra_syntax::{ast, AstToken, SyntaxNode, SyntaxToken, TextRange, TextSize};
-use stdx::SepBy;
 use crate::{
    call_info::ActiveParameter, Analysis, Highlight, HighlightModifier, HighlightTag,
@@ -129,8 +129,7 @@ pub(super) fn extract_doc_comments(
            line[pos..].to_owned()
        })
-        .sep_by("\n")
+        .join("\n");
-        .to_string();
    if doctest.is_empty() {
        return None;
diff --git a/crates/ra_ide/src/syntax_highlighting/tests.rs b/crates/ra_ide/src/syntax_highlighting/tests.rs
index 2deee404c..a8087635a 100644
--- a/crates/ra_ide/src/syntax_highlighting/tests.rs
+++ b/crates/ra_ide/src/syntax_highlighting/tests.rs
@@ -275,19 +275,64 @@ fn test_unsafe_highlighting() {
        r#"
 unsafe fn unsafe_fn() {}
+union Union {
+    a: u32,
+    b: f32,
+}
 struct HasUnsafeFn;
 impl HasUnsafeFn {
    unsafe fn unsafe_method(&self) {}
 }
+struct TypeForStaticMut {
+    a: u8
+}
+static mut global_mut: TypeForStaticMut = TypeForStaticMut { a: 0 };
+#[repr(packed)]
+struct Packed {
+    a: u16,
+}
+trait DoTheAutoref {
+    fn calls_autoref(&self);
+}
+impl DoTheAutoref for u16 {
+    fn calls_autoref(&self) {}
+}
 fn main() {
-    let x = &5 as *const usize;
+    let x = &5 as *const _ as *const usize;
+    let u = Union { b: 0 };
    unsafe {
+        // unsafe fn and method calls
        unsafe_fn();
+        let b = u.b;
+        match u {
+            Union { b: 0 } => (),
+            Union { a } => (),
+        }
        HasUnsafeFn.unsafe_method();
-        let y = *(x);
-        let z = -x;
+        // unsafe deref
+        let y = *x;
+        // unsafe access to a static mut
+        let a = global_mut.a;
+        // unsafe ref of packed fields
+        let packed = Packed { a: 0 };
+        let a = &packed.a;
+        let ref a = packed.a;
+        let Packed { ref a } = packed;
+        let Packed { a: ref _a } = packed;
+        // unsafe auto ref of packed field
+        packed.a.calls_autoref();
    }
 }
 "#
@@ -373,6 +418,23 @@ macro_rules! noop {
    );
 }
+#[test]
+fn test_extern_crate() {
+    check_highlighting(
+        r#"
+        //- /main.rs
+        extern crate std;
+        extern crate alloc as abc;
+        //- /std/lib.rs
+        pub struct S;
+        //- /alloc/lib.rs
+        pub struct A
+        "#,
+        expect_file!["crates/ra_ide/test_data/highlight_extern_crate.html"],
+        false,
+    );
+}
 /// Highlights the code given by the `ra_fixture` argument, renders the
 /// result as HTML, and compares it with the HTML file given as `snapshot`.
 /// Note that the `snapshot` file is overwritten by the rendered HTML.
diff --git a/crates/ra_ide/test_data/highlight_extern_crate.html b/crates/ra_ide/test_data/highlight_extern_crate.html
new file mode 100644
index 000000000..800d894c7
--- /dev/null
+++ b/crates/ra_ide/test_data/highlight_extern_crate.html
@@ -0,0 +1,40 @@
+<style>
+body                { margin: 0; }
+pre                 { color: #DCDCCC; background: #3F3F3F; font-size: 22px; padding: 0.4em; }
+.lifetime           { color: #DFAF8F; font-style: italic; }
+.comment            { color: #7F9F7F; }
+.documentation      { color: #629755; }
+.injected           { opacity: 0.65 ; }
+.struct, .enum      { color: #7CB8BB; }
+.enum_variant       { color: #BDE0F3; }
+.string_literal     { color: #CC9393; }
+.field              { color: #94BFF3; }
+.function           { color: #93E0E3; }
+.function.unsafe    { color: #BC8383; }
+.operator.unsafe    { color: #BC8383; }
+.parameter          { color: #94BFF3; }
+.text               { color: #DCDCCC; }
+.type               { color: #7CB8BB; }
+.builtin_type       { color: #8CD0D3; }
+.type_param         { color: #DFAF8F; }
+.attribute          { color: #94BFF3; }
+.numeric_literal    { color: #BFEBBF; }
+.bool_literal       { color: #BFE6EB; }
+.macro              { color: #94BFF3; }
+.module             { color: #AFD8AF; }
+.value_param        { color: #DCDCCC; }
+.variable           { color: #DCDCCC; }
+.format_specifier   { color: #CC696B; }
+.mutable            { text-decoration: underline; }
+.escape_sequence    { color: #94BFF3; }
+.keyword            { color: #F0DFAF; font-weight: bold; }
+.keyword.unsafe     { color: #BC8383; font-weight: bold; }
+.control            { font-style: italic; }
+.unresolved_reference { color: #FC5555; text-decoration: wavy underline; }
+</style>
+<pre><code><span class="keyword">extern</span> <span class="keyword">crate</span> <span class="module">std</span><span class="punctuation">;</span>
+<span class="keyword">extern</span> <span class="keyword">crate</span> <span class="module">alloc</span> <span class="keyword">as</span> <span class="module">abc</span><span class="punctuation">;</span>
+</code></pre>
+\ No newline at end of file
diff --git a/crates/ra_ide/test_data/highlight_unsafe.html b/crates/ra_ide/test_data/highlight_unsafe.html
index b81b6f1c3..552fea668 100644
--- a/crates/ra_ide/test_data/highlight_unsafe.html
+++ b/crates/ra_ide/test_data/highlight_unsafe.html
@@ -37,18 +37,63 @@ pre                 { color: #DCDCCC; background: #3F3F3F; font-size: 22px; padd
 </style>
 <pre><code><span class="keyword unsafe">unsafe</span> <span class="keyword">fn</span> <span class="function declaration unsafe">unsafe_fn</span><span class="punctuation">(</span><span class="punctuation">)</span> <span class="punctuation">{</span><span class="punctuation">}</span>
+<span class="keyword">union</span> <span class="union declaration">Union</span> <span class="punctuation">{</span>
+    <span class="field declaration">a</span><span class="punctuation">:</span> <span class="builtin_type">u32</span><span class="punctuation">,</span>
+    <span class="field declaration">b</span><span class="punctuation">:</span> <span class="builtin_type">f32</span><span class="punctuation">,</span>
+<span class="punctuation">}</span>
 <span class="keyword">struct</span> <span class="struct declaration">HasUnsafeFn</span><span class="punctuation">;</span>
 <span class="keyword">impl</span> <span class="struct">HasUnsafeFn</span> <span class="punctuation">{</span>
    <span class="keyword unsafe">unsafe</span> <span class="keyword">fn</span> <span class="function declaration unsafe">unsafe_method</span><span class="punctuation">(</span><span class="operator">&</span><span class="self_keyword">self</span><span class="punctuation">)</span> <span class="punctuation">{</span><span class="punctuation">}</span>
 <span class="punctuation">}</span>
+<span class="keyword">struct</span> <span class="struct declaration">TypeForStaticMut</span> <span class="punctuation">{</span>
+    <span class="field declaration">a</span><span class="punctuation">:</span> <span class="builtin_type">u8</span>
+<span class="punctuation">}</span>
+<span class="keyword">static</span> <span class="keyword">mut</span> <span class="static declaration mutable unsafe">global_mut</span><span class="punctuation">:</span> <span class="struct">TypeForStaticMut</span> <span class="operator">=</span> <span class="struct">TypeForStaticMut</span> <span class="punctuation">{</span> <span class="field">a</span><span class="punctuation">:</span> <span class="numeric_literal">0</span> <span class="punctuation">}</span><span class="punctuation">;</span>
+<span class="attribute">#</span><span class="attribute">[</span><span class="function attribute">repr</span><span class="punctuation">(</span><span class="attribute">packed</span><span class="punctuation">)</span><span class="attribute">]</span>
+<span class="keyword">struct</span> <span class="struct declaration">Packed</span> <span class="punctuation">{</span>
+    <span class="field declaration">a</span><span class="punctuation">:</span> <span class="builtin_type">u16</span><span class="punctuation">,</span>
+<span class="punctuation">}</span>
+<span class="keyword">trait</span> <span class="trait declaration">DoTheAutoref</span> <span class="punctuation">{</span>
+    <span class="keyword">fn</span> <span class="function declaration">calls_autoref</span><span class="punctuation">(</span><span class="operator">&</span><span class="self_keyword">self</span><span class="punctuation">)</span><span class="punctuation">;</span>
+<span class="punctuation">}</span>
+<span class="keyword">impl</span> <span class="trait">DoTheAutoref</span> <span class="keyword">for</span> <span class="builtin_type">u16</span> <span class="punctuation">{</span>
+    <span class="keyword">fn</span> <span class="function declaration">calls_autoref</span><span class="punctuation">(</span><span class="operator">&</span><span class="self_keyword">self</span><span class="punctuation">)</span> <span class="punctuation">{</span><span class="punctuation">}</span>
+<span class="punctuation">}</span>
 <span class="keyword">fn</span> <span class="function declaration">main</span><span class="punctuation">(</span><span class="punctuation">)</span> <span class="punctuation">{</span>
-    <span class="keyword">let</span> <span class="variable declaration">x</span> <span class="operator">=</span> <span class="operator">&</span><span class="numeric_literal">5</span> <span class="keyword">as</span> <span class="keyword">*</span><span class="keyword">const</span> <span class="builtin_type">usize</span><span class="punctuation">;</span>
+    <span class="keyword">let</span> <span class="variable declaration">x</span> <span class="operator">=</span> <span class="operator">&</span><span class="numeric_literal">5</span> <span class="keyword">as</span> <span class="keyword">*</span><span class="keyword">const</span> <span class="punctuation">_</span> <span class="keyword">as</span> <span class="keyword">*</span><span class="keyword">const</span> <span class="builtin_type">usize</span><span class="punctuation">;</span>
+    <span class="keyword">let</span> <span class="variable declaration">u</span> <span class="operator">=</span> <span class="union">Union</span> <span class="punctuation">{</span> <span class="field">b</span><span class="punctuation">:</span> <span class="numeric_literal">0</span> <span class="punctuation">}</span><span class="punctuation">;</span>
    <span class="keyword unsafe">unsafe</span> <span class="punctuation">{</span>
+        <span class="comment">// unsafe fn and method calls</span>
        <span class="function unsafe">unsafe_fn</span><span class="punctuation">(</span><span class="punctuation">)</span><span class="punctuation">;</span>
+        <span class="keyword">let</span> <span class="variable declaration">b</span> <span class="operator">=</span> <span class="variable">u</span><span class="punctuation">.</span><span class="field unsafe">b</span><span class="punctuation">;</span>
+        <span class="keyword control">match</span> <span class="variable">u</span> <span class="punctuation">{</span>
+            <span class="union">Union</span> <span class="punctuation">{</span> <span class="field unsafe">b</span><span class="punctuation">:</span> <span class="numeric_literal">0</span> <span class="punctuation">}</span> <span class="operator">=&gt;</span> <span class="punctuation">(</span><span class="punctuation">)</span><span class="punctuation">,</span>
+            <span class="union">Union</span> <span class="punctuation">{</span> <span class="field unsafe">a</span> <span class="punctuation">}</span> <span class="operator">=&gt;</span> <span class="punctuation">(</span><span class="punctuation">)</span><span class="punctuation">,</span>
+        <span class="punctuation">}</span>
        <span class="struct">HasUnsafeFn</span><span class="punctuation">.</span><span class="function unsafe">unsafe_method</span><span class="punctuation">(</span><span class="punctuation">)</span><span class="punctuation">;</span>
-        <span class="keyword">let</span> <span class="variable declaration">y</span> <span class="operator">=</span> <span class="operator unsafe">*</span><span class="punctuation">(</span><span class="variable">x</span><span class="punctuation">)</span><span class="punctuation">;</span>
-        <span class="keyword">let</span> <span class="variable declaration">z</span> <span class="operator">=</span> <span class="numeric_literal">-</span><span class="variable">x</span><span class="punctuation">;</span>
+        <span class="comment">// unsafe deref</span>
+        <span class="keyword">let</span> <span class="variable declaration">y</span> <span class="operator">=</span> <span class="operator unsafe">*</span><span class="variable">x</span><span class="punctuation">;</span>
+        <span class="comment">// unsafe access to a static mut</span>
+        <span class="keyword">let</span> <span class="variable declaration">a</span> <span class="operator">=</span> <span class="static mutable unsafe">global_mut</span><span class="punctuation">.</span><span class="field">a</span><span class="punctuation">;</span>
+        <span class="comment">// unsafe ref of packed fields</span>
+        <span class="keyword">let</span> <span class="variable declaration">packed</span> <span class="operator">=</span> <span class="struct">Packed</span> <span class="punctuation">{</span> <span class="field">a</span><span class="punctuation">:</span> <span class="numeric_literal">0</span> <span class="punctuation">}</span><span class="punctuation">;</span>
+        <span class="keyword">let</span> <span class="variable declaration">a</span> <span class="operator">=</span> <span class="operator unsafe">&</span><span class="variable">packed</span><span class="punctuation">.</span><span class="field">a</span><span class="punctuation">;</span>
+        <span class="keyword">let</span> <span class="keyword unsafe">ref</span> <span class="variable declaration">a</span> <span class="operator">=</span> <span class="variable">packed</span><span class="punctuation">.</span><span class="field">a</span><span class="punctuation">;</span>
+        <span class="keyword">let</span> <span class="struct">Packed</span> <span class="punctuation">{</span> <span class="keyword unsafe">ref</span> <span class="field">a</span> <span class="punctuation">}</span> <span class="operator">=</span> <span class="variable">packed</span><span class="punctuation">;</span>
+        <span class="keyword">let</span> <span class="struct">Packed</span> <span class="punctuation">{</span> <span class="field">a</span><span class="punctuation">:</span> <span class="keyword unsafe">ref</span> <span class="variable declaration">_a</span> <span class="punctuation">}</span> <span class="operator">=</span> <span class="variable">packed</span><span class="punctuation">;</span>