Move unsafe packed ref logic to Semantics, use `Attrs::by_key` to simplify repr attr lookup

4 files changed, 815 insertions, 54 deletions

diff --git a/crates/ra_hir/src/semantics.rs b/crates/ra_hir/src/semantics.rs
index e392130ab6d..1072b397185 100644
--- a/crates/ra_hir/src/semantics.rs
+++ b/crates/ra_hir/src/semantics.rs
@@ -279,6 +279,47 @@ 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_pat(&self, pat: &ast::Pat) -> bool {
+        let ty = (|| {
+            let parent = match pat {
+                ast::Pat::BindPat(bind_pat) => bind_pat.syntax().parent()?,
+                _ => return None,
+            };
+
+            // `BindPat` can live under `RecordPat` directly under `RecordFieldPat` or
+            // `RecordFieldPatList`. `RecordFieldPat` also lives under `RecordFieldPatList`,
+            // so this tries to lookup the `BindPat` anywhere along that structure to the
+            // `RecordPat` so we can get the containing type.
+            let record_pat = ast::RecordFieldPat::cast(parent.clone())
+                .and_then(|record_pat| record_pat.syntax().parent())
+                .or_else(|| Some(parent.clone()))
+                .and_then(|parent| {
+                    ast::RecordFieldPatList::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.
+        ty.map(|ty| ty.is_packed(self.db)).unwrap_or(false)
+    }
 }
 
 impl<'db> SemanticsImpl<'db> {
diff --git a/crates/ra_hir_def/src/adt.rs b/crates/ra_hir_def/src/adt.rs
index 4ba6944805d..35c3a914025 100644
--- a/crates/ra_hir_def/src/adt.rs
+++ b/crates/ra_hir_def/src/adt.rs
@@ -12,11 +12,9 @@ use ra_syntax::ast::{self, NameOwner, VisibilityOwner};
 use tt::{Delimiter, DelimiterKind, Leaf, Subtree, TokenTree};
 
 use crate::{
-    attr::{Attr, AttrInput},
     body::{CfgExpander, LowerCtx},
     db::DefDatabase,
     item_tree::{AttrOwner, Field, Fields, ItemTree, ModItem},
-    path::{ModPath, PathKind},
     src::HasChildSource,
     src::HasSource,
     trace::Trace,
@@ -69,21 +67,7 @@ pub enum ReprKind {
 }
 
 fn repr_from_value(item_tree: &ItemTree, of: AttrOwner) -> Option<ReprKind> {
-    item_tree.attrs(of).iter().find_map(|a| {
-        if let Attr {
-            path: ModPath { kind: PathKind::Plain, segments },
-            input: Some(AttrInput::TokenTree(subtree)),
-        } = a
-        {
-            if segments.len() == 1 && segments[0].to_string() == "repr" {
-                parse_repr_tt(subtree)
-            } else {
-                None
-            }
-        } else {
-            None
-        }
-    })
+    item_tree.attrs(of).by_key("repr").tt_values().find_map(parse_repr_tt)
 }
 
 fn parse_repr_tt(tt: &Subtree) -> Option<ReprKind> {
@@ -93,11 +77,8 @@ fn parse_repr_tt(tt: &Subtree) -> Option<ReprKind> {
     }
 
     let mut it = tt.token_trees.iter();
-    match it.next() {
-        None => None,
-        Some(TokenTree::Leaf(Leaf::Ident(ident))) if ident.text == "packed" => {
-            Some(ReprKind::Packed)
-        }
+    match it.next()? {
+        TokenTree::Leaf(Leaf::Ident(ident)) if ident.text == "packed" => Some(ReprKind::Packed),
         _ => Some(ReprKind::Other),
     }
 }
diff --git a/crates/ra_ide/src/call_info.rs.orig b/crates/ra_ide/src/call_info.rs.orig
new file mode 100644
index 00000000000..0e04c0b6076
--- /dev/null
+++ b/crates/ra_ide/src/call_info.rs.orig
@@ -0,0 +1,769 @@
+//! FIXME: write short doc here
+use either::Either;
+use hir::{Docs, HirDisplay, Semantics, Type};
+use ra_ide_db::RootDatabase;
+use ra_syntax::{
+    ast::{self, ArgListOwner},
+    match_ast, AstNode, SyntaxNode, SyntaxToken, TextRange, TextSize,
+};
+use stdx::format_to;
+use test_utils::mark;
+
+use crate::FilePosition;
+
+/// Contains information about a call site. Specifically the
+/// `FunctionSignature`and current parameter.
+#[derive(Debug)]
+pub struct CallInfo {
+    pub doc: Option<String>,
+    pub signature: String,
+    pub active_parameter: Option<usize>,
+    parameters: Vec<TextRange>,
+}
+
+impl CallInfo {
+    pub fn parameter_labels(&self) -> impl Iterator<Item = &str> + '_ {
+        self.parameters.iter().map(move |&it| &self.signature[it])
+    }
+    pub fn parameter_ranges(&self) -> &[TextRange] {
+        &self.parameters
+    }
+    fn push_param(&mut self, param: &str) {
+        if !self.signature.ends_with('(') {
+            self.signature.push_str(", ");
+        }
+        let start = TextSize::of(&self.signature);
+        self.signature.push_str(param);
+        let end = TextSize::of(&self.signature);
+        self.parameters.push(TextRange::new(start, end))
+    }
+}
+
+/// Computes parameter information for the given call expression.
+pub(crate) fn call_info(db: &RootDatabase, position: FilePosition) -> Option<CallInfo> {
+    let sema = Semantics::new(db);
+    let file = sema.parse(position.file_id);
+    let file = file.syntax();
+    let token = file.token_at_offset(position.offset).next()?;
+    let token = sema.descend_into_macros(token);
+
+    let (callable, active_parameter) = call_info_impl(&sema, token)?;
+
+    let mut res =
+        CallInfo { doc: None, signature: String::new(), parameters: vec![], active_parameter };
+
+    match callable.kind() {
+        hir::CallableKind::Function(func) => {
+            res.doc = func.docs(db).map(|it| it.as_str().to_string());
+            format_to!(res.signature, "fn {}", func.name(db));
+        }
+        hir::CallableKind::TupleStruct(strukt) => {
+            res.doc = strukt.docs(db).map(|it| it.as_str().to_string());
+            format_to!(res.signature, "struct {}", strukt.name(db));
+        }
+        hir::CallableKind::TupleEnumVariant(variant) => {
+            res.doc = variant.docs(db).map(|it| it.as_str().to_string());
+            format_to!(
+                res.signature,
+                "enum {}::{}",
+                variant.parent_enum(db).name(db),
+                variant.name(db)
+            );
+        }
+        hir::CallableKind::Closure => (),
+    }
+
+    res.signature.push('(');
+    {
+        if let Some(self_param) = callable.receiver_param(db) {
+            format_to!(res.signature, "{}", self_param)
+        }
+        let mut buf = String::new();
+        for (pat, ty) in callable.params(db) {
+            buf.clear();
+            if let Some(pat) = pat {
+                match pat {
+                    Either::Left(_self) => format_to!(buf, "self: "),
+                    Either::Right(pat) => format_to!(buf, "{}: ", pat),
+                }
+            }
+            format_to!(buf, "{}", ty.display(db));
+            res.push_param(&buf);
+        }
+    }
+    res.signature.push(')');
+
+    match callable.kind() {
+        hir::CallableKind::Function(_) | hir::CallableKind::Closure => {
+            let ret_type = callable.return_type();
+            if !ret_type.is_unit() {
+                format_to!(res.signature, " -> {}", ret_type.display(db));
+            }
+        }
+        hir::CallableKind::TupleStruct(_) | hir::CallableKind::TupleEnumVariant(_) => {}
+    }
+    Some(res)
+}
+
+fn call_info_impl(
+    sema: &Semantics<RootDatabase>,
+    token: SyntaxToken,
+) -> Option<(hir::Callable, Option<usize>)> {
+    // Find the calling expression and it's NameRef
+    let calling_node = FnCallNode::with_node(&token.parent())?;
+
+<<<<<<< HEAD
+    let callable = match &calling_node {
+        FnCallNode::CallExpr(call) => sema.type_of_expr(&call.expr()?)?.as_callable(sema.db)?,
+        FnCallNode::MethodCallExpr(call) => sema.resolve_method_call_as_callable(call)?,
+    };
+    let active_param = if let Some(arg_list) = calling_node.arg_list() {
+        // Number of arguments specified at the call site
+        let num_args_at_callsite = arg_list.args().count();
+
+        let arg_list_range = arg_list.syntax().text_range();
+        if !arg_list_range.contains_inclusive(token.text_range().start()) {
+            mark::hit!(call_info_bad_offset);
+            return None;
+=======
+    let (mut call_info, has_self) = match &calling_node {
+        FnCallNode::CallExpr(call) => {
+            //FIXME: Type::as_callable is broken
+            let callable_def = sema.type_of_expr(&call.expr()?)?.as_callable()?;
+            match callable_def {
+                hir::CallableDef::FunctionId(it) => {
+                    let fn_def = it.into();
+                    (CallInfo::with_fn(sema.db, fn_def), fn_def.has_self_param(sema.db))
+                }
+                hir::CallableDef::StructId(it) => {
+                    (CallInfo::with_struct(sema.db, it.into())?, false)
+                }
+                hir::CallableDef::EnumVariantId(it) => {
+                    (CallInfo::with_enum_variant(sema.db, it.into())?, false)
+                }
+            }
+        }
+        FnCallNode::MethodCallExpr(method_call) => {
+            let function = sema.resolve_method_call(&method_call)?;
+            (CallInfo::with_fn(sema.db, function), function.has_self_param(sema.db))
+        }
+        FnCallNode::MacroCallExpr(macro_call) => {
+            let macro_def = sema.resolve_macro_call(&macro_call)?;
+            (CallInfo::with_macro(sema.db, macro_def)?, false)
+>>>>>>> Revert function structs back to using bool to track self param, use first param for self information in syntax highlighting instead
+        }
+        let param = std::cmp::min(
+            num_args_at_callsite,
+            arg_list
+                .args()
+                .take_while(|arg| arg.syntax().text_range().end() <= token.text_range().start())
+                .count(),
+        );
+
+        Some(param)
+    } else {
+        None
+    };
+    Some((callable, active_param))
+}
+
+#[derive(Debug)]
+pub(crate) struct ActiveParameter {
+    pub(crate) ty: Type,
+    pub(crate) name: String,
+}
+
+impl ActiveParameter {
+    pub(crate) fn at(db: &RootDatabase, position: FilePosition) -> Option<Self> {
+        let sema = Semantics::new(db);
+        let file = sema.parse(position.file_id);
+        let file = file.syntax();
+        let token = file.token_at_offset(position.offset).next()?;
+        let token = sema.descend_into_macros(token);
+        Self::at_token(&sema, token)
+    }
+
+    pub(crate) fn at_token(sema: &Semantics<RootDatabase>, token: SyntaxToken) -> Option<Self> {
+        let (signature, active_parameter) = call_info_impl(&sema, token)?;
+
+        let idx = active_parameter?;
+        let mut params = signature.params(sema.db);
+        if !(idx < params.len()) {
+            mark::hit!(too_many_arguments);
+            return None;
+        }
+        let (pat, ty) = params.swap_remove(idx);
+        let name = pat?.to_string();
+        Some(ActiveParameter { ty, name })
+    }
+}
+
+#[derive(Debug)]
+pub(crate) enum FnCallNode {
+    CallExpr(ast::CallExpr),
+    MethodCallExpr(ast::MethodCallExpr),
+}
+
+impl FnCallNode {
+    fn with_node(syntax: &SyntaxNode) -> Option<FnCallNode> {
+        syntax.ancestors().find_map(|node| {
+            match_ast! {
+                match node {
+                    ast::CallExpr(it) => Some(FnCallNode::CallExpr(it)),
+                    ast::MethodCallExpr(it) => {
+                        let arg_list = it.arg_list()?;
+                        if !arg_list.syntax().text_range().contains_range(syntax.text_range()) {
+                            return None;
+                        }
+                        Some(FnCallNode::MethodCallExpr(it))
+                    },
+                    _ => None,
+                }
+            }
+        })
+    }
+
+    pub(crate) fn with_node_exact(node: &SyntaxNode) -> Option<FnCallNode> {
+        match_ast! {
+            match node {
+                ast::CallExpr(it) => Some(FnCallNode::CallExpr(it)),
+                ast::MethodCallExpr(it) => Some(FnCallNode::MethodCallExpr(it)),
+                _ => None,
+            }
+        }
+    }
+
+    pub(crate) fn name_ref(&self) -> Option<ast::NameRef> {
+        match self {
+            FnCallNode::CallExpr(call_expr) => Some(match call_expr.expr()? {
+                ast::Expr::PathExpr(path_expr) => path_expr.path()?.segment()?.name_ref()?,
+                _ => return None,
+            }),
+
+            FnCallNode::MethodCallExpr(call_expr) => {
+                call_expr.syntax().children().filter_map(ast::NameRef::cast).next()
+            }
+        }
+    }
+
+    fn arg_list(&self) -> Option<ast::ArgList> {
+        match self {
+            FnCallNode::CallExpr(expr) => expr.arg_list(),
+            FnCallNode::MethodCallExpr(expr) => expr.arg_list(),
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use expect::{expect, Expect};
+    use test_utils::mark;
+
+    use crate::mock_analysis::analysis_and_position;
+
+    fn check(ra_fixture: &str, expect: Expect) {
+        let (analysis, position) = analysis_and_position(ra_fixture);
+        let call_info = analysis.call_info(position).unwrap();
+        let actual = match call_info {
+            Some(call_info) => {
+                let docs = match &call_info.doc {
+                    None => "".to_string(),
+                    Some(docs) => format!("{}\n------\n", docs.as_str()),
+                };
+                let params = call_info
+                    .parameter_labels()
+                    .enumerate()
+                    .map(|(i, param)| {
+                        if Some(i) == call_info.active_parameter {
+                            format!("<{}>", param)
+                        } else {
+                            param.to_string()
+                        }
+                    })
+                    .collect::<Vec<_>>()
+                    .join(", ");
+                format!("{}{}\n({})\n", docs, call_info.signature, params)
+            }
+            None => String::new(),
+        };
+        expect.assert_eq(&actual);
+    }
+
+    #[test]
+    fn test_fn_signature_two_args() {
+        check(
+            r#"
+fn foo(x: u32, y: u32) -> u32 {x + y}
+fn bar() { foo(<|>3, ); }
+"#,
+            expect![[r#"
+                fn foo(x: u32, y: u32) -> u32
+                (<x: u32>, y: u32)
+            "#]],
+        );
+        check(
+            r#"
+fn foo(x: u32, y: u32) -> u32 {x + y}
+fn bar() { foo(3<|>, ); }
+"#,
+            expect![[r#"
+                fn foo(x: u32, y: u32) -> u32
+                (<x: u32>, y: u32)
+            "#]],
+        );
+        check(
+            r#"
+fn foo(x: u32, y: u32) -> u32 {x + y}
+fn bar() { foo(3,<|> ); }
+"#,
+            expect![[r#"
+                fn foo(x: u32, y: u32) -> u32
+                (x: u32, <y: u32>)
+            "#]],
+        );
+        check(
+            r#"
+fn foo(x: u32, y: u32) -> u32 {x + y}
+fn bar() { foo(3, <|>); }
+"#,
+            expect![[r#"
+                fn foo(x: u32, y: u32) -> u32
+                (x: u32, <y: u32>)
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_fn_signature_two_args_empty() {
+        check(
+            r#"
+fn foo(x: u32, y: u32) -> u32 {x + y}
+fn bar() { foo(<|>); }
+"#,
+            expect![[r#"
+                fn foo(x: u32, y: u32) -> u32
+                (<x: u32>, y: u32)
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_fn_signature_two_args_first_generics() {
+        check(
+            r#"
+fn foo<T, U: Copy + Display>(x: T, y: U) -> u32
+    where T: Copy + Display, U: Debug
+{ x + y }
+
+fn bar() { foo(<|>3, ); }
+"#,
+            expect![[r#"
+                fn foo(x: i32, y: {unknown}) -> u32
+                (<x: i32>, y: {unknown})
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_fn_signature_no_params() {
+        check(
+            r#"
+fn foo<T>() -> T where T: Copy + Display {}
+fn bar() { foo(<|>); }
+"#,
+            expect![[r#"
+                fn foo() -> {unknown}
+                ()
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_fn_signature_for_impl() {
+        check(
+            r#"
+struct F;
+impl F { pub fn new() { } }
+fn bar() {
+    let _ : F = F::new(<|>);
+}
+"#,
+            expect![[r#"
+                fn new()
+                ()
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_fn_signature_for_method_self() {
+        check(
+            r#"
+struct S;
+impl S { pub fn do_it(&self) {} }
+
+fn bar() {
+    let s: S = S;
+    s.do_it(<|>);
+}
+"#,
+            expect![[r#"
+                fn do_it(&self)
+                ()
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_fn_signature_for_method_with_arg() {
+        check(
+            r#"
+struct S;
+impl S {
+    fn foo(&self, x: i32) {}
+}
+
+fn main() { S.foo(<|>); }
+"#,
+            expect![[r#"
+                fn foo(&self, x: i32)
+                (<x: i32>)
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_fn_signature_for_method_with_arg_as_assoc_fn() {
+        check(
+            r#"
+struct S;
+impl S {
+    fn foo(&self, x: i32) {}
+}
+
+fn main() { S::foo(<|>); }
+"#,
+            expect![[r#"
+                fn foo(self: &S, x: i32)
+                (<self: &S>, x: i32)
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_fn_signature_with_docs_simple() {
+        check(
+            r#"
+/// test
+// non-doc-comment
+fn foo(j: u32) -> u32 {
+    j
+}
+
+fn bar() {
+    let _ = foo(<|>);
+}
+"#,
+            expect![[r#"
+                test
+                ------
+                fn foo(j: u32) -> u32
+                (<j: u32>)
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_fn_signature_with_docs() {
+        check(
+            r#"
+/// Adds one to the number given.
+///
+/// # Examples
+///
+/// ```
+/// let five = 5;
+///
+/// assert_eq!(6, my_crate::add_one(5));
+/// ```
+pub fn add_one(x: i32) -> i32 {
+    x + 1
+}
+
+pub fn do() {
+    add_one(<|>
+}"#,
+            expect![[r##"
+                Adds one to the number given.
+
+                # Examples
+
+                ```
+                let five = 5;
+
+                assert_eq!(6, my_crate::add_one(5));
+                ```
+                ------
+                fn add_one(x: i32) -> i32
+                (<x: i32>)
+            "##]],
+        );
+    }
+
+    #[test]
+    fn test_fn_signature_with_docs_impl() {
+        check(
+            r#"
+struct addr;
+impl addr {
+    /// Adds one to the number given.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// let five = 5;
+    ///
+    /// assert_eq!(6, my_crate::add_one(5));
+    /// ```
+    pub fn add_one(x: i32) -> i32 {
+        x + 1
+    }
+}
+
+pub fn do_it() {
+    addr {};
+    addr::add_one(<|>);
+}
+"#,
+            expect![[r##"
+                Adds one to the number given.
+
+                # Examples
+
+                ```
+                let five = 5;
+
+                assert_eq!(6, my_crate::add_one(5));
+                ```
+                ------
+                fn add_one(x: i32) -> i32
+                (<x: i32>)
+            "##]],
+        );
+    }
+
+    #[test]
+    fn test_fn_signature_with_docs_from_actix() {
+        check(
+            r#"
+struct WriteHandler<E>;
+
+impl<E> WriteHandler<E> {
+    /// Method is called when writer emits error.
+    ///
+    /// If this method returns `ErrorAction::Continue` writer processing
+    /// continues otherwise stream processing stops.
+    fn error(&mut self, err: E, ctx: &mut Self::Context) -> Running {
+        Running::Stop
+    }
+
+    /// Method is called when writer finishes.
+    ///
+    /// By default this method stops actor's `Context`.
+    fn finished(&mut self, ctx: &mut Self::Context) {
+        ctx.stop()
+    }
+}
+
+pub fn foo(mut r: WriteHandler<()>) {
+    r.finished(<|>);
+}
+"#,
+            expect![[r#"
+                Method is called when writer finishes.
+
+                By default this method stops actor's `Context`.
+                ------
+                fn finished(&mut self, ctx: &mut {unknown})
+                (<ctx: &mut {unknown}>)
+            "#]],
+        );
+    }
+
+    #[test]
+    fn call_info_bad_offset() {
+        mark::check!(call_info_bad_offset);
+        check(
+            r#"
+fn foo(x: u32, y: u32) -> u32 {x + y}
+fn bar() { foo <|> (3, ); }
+"#,
+            expect![[""]],
+        );
+    }
+
+    #[test]
+    fn test_nested_method_in_lambda() {
+        check(
+            r#"
+struct Foo;
+impl Foo { fn bar(&self, _: u32) { } }
+
+fn bar(_: u32) { }
+
+fn main() {
+    let foo = Foo;
+    std::thread::spawn(move || foo.bar(<|>));
+}
+"#,
+            expect![[r#"
+                fn bar(&self, _: u32)
+                (<_: u32>)
+            "#]],
+        );
+    }
+
+    #[test]
+    fn works_for_tuple_structs() {
+        check(
+            r#"
+/// A cool tuple struct
+struct S(u32, i32);
+fn main() {
+    let s = S(0, <|>);
+}
+"#,
+            expect![[r#"
+                A cool tuple struct
+                ------
+                struct S(u32, i32)
+                (u32, <i32>)
+            "#]],
+        );
+    }
+
+    #[test]
+    fn generic_struct() {
+        check(
+            r#"
+struct S<T>(T);
+fn main() {
+    let s = S(<|>);
+}
+"#,
+            expect![[r#"
+                struct S({unknown})
+                (<{unknown}>)
+            "#]],
+        );
+    }
+
+    #[test]
+    fn works_for_enum_variants() {
+        check(
+            r#"
+enum E {
+    /// A Variant
+    A(i32),
+    /// Another
+    B,
+    /// And C
+    C { a: i32, b: i32 }
+}
+
+fn main() {
+    let a = E::A(<|>);
+}
+"#,
+            expect![[r#"
+                A Variant
+                ------
+                enum E::A(i32)
+                (<i32>)
+            "#]],
+        );
+    }
+
+    #[test]
+    fn cant_call_struct_record() {
+        check(
+            r#"
+struct S { x: u32, y: i32 }
+fn main() {
+    let s = S(<|>);
+}
+"#,
+            expect![[""]],
+        );
+    }
+
+    #[test]
+    fn cant_call_enum_record() {
+        check(
+            r#"
+enum E {
+    /// A Variant
+    A(i32),
+    /// Another
+    B,
+    /// And C
+    C { a: i32, b: i32 }
+}
+
+fn main() {
+    let a = E::C(<|>);
+}
+"#,
+            expect![[""]],
+        );
+    }
+
+    #[test]
+    fn fn_signature_for_call_in_macro() {
+        check(
+            r#"
+macro_rules! id { ($($tt:tt)*) => { $($tt)* } }
+fn foo() { }
+id! {
+    fn bar() { foo(<|>); }
+}
+"#,
+            expect![[r#"
+                fn foo()
+                ()
+            "#]],
+        );
+    }
+
+    #[test]
+    fn call_info_for_lambdas() {
+        check(
+            r#"
+struct S;
+fn foo(s: S) -> i32 { 92 }
+fn main() {
+    (|s| foo(s))(<|>)
+}
+        "#,
+            expect![[r#"
+                (S) -> i32
+                (<S>)
+            "#]],
+        )
+    }
+
+    #[test]
+    fn call_info_for_fn_ptr() {
+        check(
+            r#"
+fn main(f: fn(i32, f64) -> char) {
+    f(0, <|>)
+}
+        "#,
+            expect![[r#"
+                (i32, f64) -> char
+                (i32, <f64>)
+            "#]],
+        )
+    }
+}
diff --git a/crates/ra_ide/src/syntax_highlighting.rs b/crates/ra_ide/src/syntax_highlighting.rs
index d5a5f69cca3..cf93205b6e3 100644
--- a/crates/ra_ide/src/syntax_highlighting.rs
+++ b/crates/ra_ide/src/syntax_highlighting.rs
@@ -671,41 +671,11 @@ fn highlight_element(
                 T![ref] => {
                     let modifier: Option<HighlightModifier> = (|| {
                         let bind_pat = element.parent().and_then(ast::BindPat::cast)?;
-                        let parent = bind_pat.syntax().parent()?;
-
-                        let ty = if let Some(pat_list) =
-                            ast::RecordFieldPatList::cast(parent.clone())
-                        {
-                            let record_pat =
-                                pat_list.syntax().parent().and_then(ast::RecordPat::cast)?;
-                            sema.type_of_pat(&ast::Pat::RecordPat(record_pat))
-                        } else if let Some(let_stmt) = ast::LetStmt::cast(parent.clone()) {
-                            let field_expr =
-                                if let ast::Expr::FieldExpr(field_expr) = let_stmt.initializer()? {
-                                    field_expr
-                                } else {
-                                    return None;
-                                };
-
-                            sema.type_of_expr(&field_expr.expr()?)
-                        } else if let Some(record_field_pat) = ast::RecordFieldPat::cast(parent) {
-                            let record_pat = record_field_pat
-                                .syntax()
-                                .parent()
-                                .and_then(ast::RecordFieldPatList::cast)?
-                                .syntax()
-                                .parent()
-                                .and_then(ast::RecordPat::cast)?;
-                            sema.type_of_pat(&ast::Pat::RecordPat(record_pat))
+                        if sema.is_unsafe_pat(&ast::Pat::BindPat(bind_pat)) {
+                            Some(HighlightModifier::Unsafe)
                         } else {
                             None
-                        }?;
-
-                        if !ty.is_packed(db) {
-                            return None;
                         }
-
-                        Some(HighlightModifier::Unsafe)
                     })();
 
                     if let Some(modifier) = modifier {