21 files changed, 490 insertions, 63 deletions

diff --git a/crates/hir/src/lib.rs b/crates/hir/src/lib.rs
index 30e577671..e34be7e42 100644
--- a/crates/hir/src/lib.rs
+++ b/crates/hir/src/lib.rs
@@ -2199,6 +2199,7 @@ pub enum ScopeDef {
     ImplSelfType(Impl),
     AdtSelfType(Adt),
     Local(Local),
+    Label(Label),
     Unknown,
 }
 
diff --git a/crates/hir/src/semantics.rs b/crates/hir/src/semantics.rs
index 15651bb22..1198e3f0b 100644
--- a/crates/hir/src/semantics.rs
+++ b/crates/hir/src/semantics.rs
@@ -839,6 +839,10 @@ impl<'a> SemanticsScope<'a> {
                     let parent = resolver.body_owner().unwrap();
                     ScopeDef::Local(Local { parent, pat_id })
                 }
+                resolver::ScopeDef::Label(label_id) => {
+                    let parent = resolver.body_owner().unwrap();
+                    ScopeDef::Label(Label { parent, label_id })
+                }
             };
             f(name, def)
         })
diff --git a/crates/hir_def/src/body/scope.rs b/crates/hir_def/src/body/scope.rs
index 1bbb54fc6..bd7005ca6 100644
--- a/crates/hir_def/src/body/scope.rs
+++ b/crates/hir_def/src/body/scope.rs
@@ -8,7 +8,7 @@ use rustc_hash::FxHashMap;
 use crate::{
     body::Body,
     db::DefDatabase,
-    expr::{Expr, ExprId, Pat, PatId, Statement},
+    expr::{Expr, ExprId, LabelId, Pat, PatId, Statement},
     BlockId, DefWithBodyId,
 };
 
@@ -40,6 +40,7 @@ impl ScopeEntry {
 pub struct ScopeData {
     parent: Option<ScopeId>,
     block: Option<BlockId>,
+    label: Option<(LabelId, Name)>,
     entries: Vec<ScopeEntry>,
 }
 
@@ -67,6 +68,11 @@ impl ExprScopes {
         self.scopes[scope].block
     }
 
+    /// If `scope` refers to a labeled expression scope, returns the corresponding `Label`.
+    pub fn label(&self, scope: ScopeId) -> Option<(LabelId, Name)> {
+        self.scopes[scope].label.clone()
+    }
+
     pub fn scope_chain(&self, scope: Option<ScopeId>) -> impl Iterator<Item = ScopeId> + '_ {
         std::iter::successors(scope, move |&scope| self.scopes[scope].parent)
     }
@@ -85,15 +91,34 @@ impl ExprScopes {
     }
 
     fn root_scope(&mut self) -> ScopeId {
-        self.scopes.alloc(ScopeData { parent: None, block: None, entries: vec![] })
+        self.scopes.alloc(ScopeData { parent: None, block: None, label: None, entries: vec![] })
     }
 
     fn new_scope(&mut self, parent: ScopeId) -> ScopeId {
-        self.scopes.alloc(ScopeData { parent: Some(parent), block: None, entries: vec![] })
+        self.scopes.alloc(ScopeData {
+            parent: Some(parent),
+            block: None,
+            label: None,
+            entries: vec![],
+        })
     }
 
-    fn new_block_scope(&mut self, parent: ScopeId, block: BlockId) -> ScopeId {
-        self.scopes.alloc(ScopeData { parent: Some(parent), block: Some(block), entries: vec![] })
+    fn new_labeled_scope(&mut self, parent: ScopeId, label: Option<(LabelId, Name)>) -> ScopeId {
+        self.scopes.alloc(ScopeData { parent: Some(parent), block: None, label, entries: vec![] })
+    }
+
+    fn new_block_scope(
+        &mut self,
+        parent: ScopeId,
+        block: BlockId,
+        label: Option<(LabelId, Name)>,
+    ) -> ScopeId {
+        self.scopes.alloc(ScopeData {
+            parent: Some(parent),
+            block: Some(block),
+            label,
+            entries: vec![],
+        })
     }
 
     fn add_bindings(&mut self, body: &Body, scope: ScopeId, pat: PatId) {
@@ -144,21 +169,33 @@ fn compute_block_scopes(
 }
 
 fn compute_expr_scopes(expr: ExprId, body: &Body, scopes: &mut ExprScopes, scope: ScopeId) {
+    let make_label =
+        |label: &Option<_>| label.map(|label| (label, body.labels[label].name.clone()));
+
     scopes.set_scope(expr, scope);
     match &body[expr] {
-        Expr::Block { statements, tail, id, .. } => {
-            let scope = scopes.new_block_scope(scope, *id);
+        Expr::Block { statements, tail, id, label } => {
+            let scope = scopes.new_block_scope(scope, *id, make_label(label));
             // Overwrite the old scope for the block expr, so that every block scope can be found
             // via the block itself (important for blocks that only contain items, no expressions).
             scopes.set_scope(expr, scope);
-            compute_block_scopes(&statements, *tail, body, scopes, scope);
+            compute_block_scopes(statements, *tail, body, scopes, scope);
         }
-        Expr::For { iterable, pat, body: body_expr, .. } => {
+        Expr::For { iterable, pat, body: body_expr, label } => {
             compute_expr_scopes(*iterable, body, scopes, scope);
-            let scope = scopes.new_scope(scope);
+            let scope = scopes.new_labeled_scope(scope, make_label(label));
             scopes.add_bindings(body, scope, *pat);
             compute_expr_scopes(*body_expr, body, scopes, scope);
         }
+        Expr::While { condition, body: body_expr, label } => {
+            let scope = scopes.new_labeled_scope(scope, make_label(label));
+            compute_expr_scopes(*condition, body, scopes, scope);
+            compute_expr_scopes(*body_expr, body, scopes, scope);
+        }
+        Expr::Loop { body: body_expr, label } => {
+            let scope = scopes.new_labeled_scope(scope, make_label(label));
+            compute_expr_scopes(*body_expr, body, scopes, scope);
+        }
         Expr::Lambda { args, body: body_expr, .. } => {
             let scope = scopes.new_scope(scope);
             scopes.add_params_bindings(body, scope, &args);
diff --git a/crates/hir_def/src/resolver.rs b/crates/hir_def/src/resolver.rs
index 42736171e..4a2d1c087 100644
--- a/crates/hir_def/src/resolver.rs
+++ b/crates/hir_def/src/resolver.rs
@@ -12,7 +12,7 @@ use crate::{
     body::scope::{ExprScopes, ScopeId},
     builtin_type::BuiltinType,
     db::DefDatabase,
-    expr::{ExprId, PatId},
+    expr::{ExprId, LabelId, PatId},
     generics::GenericParams,
     item_scope::{BuiltinShadowMode, BUILTIN_SCOPE},
     nameres::DefMap,
@@ -409,6 +409,7 @@ pub enum ScopeDef {
     AdtSelfType(AdtId),
     GenericParam(GenericParamId),
     Local(PatId),
+    Label(LabelId),
 }
 
 impl Scope {
@@ -470,6 +471,9 @@ impl Scope {
                 f(name![Self], ScopeDef::AdtSelfType(*i));
             }
             Scope::ExprScope(scope) => {
+                if let Some((label, name)) = scope.expr_scopes.label(scope.scope_id) {
+                    f(name.clone(), ScopeDef::Label(label))
+                }
                 scope.expr_scopes.entries(scope.scope_id).iter().for_each(|e| {
                     f(e.name().clone(), ScopeDef::Local(e.pat()));
                 });
diff --git a/crates/ide/src/syntax_highlighting/inject.rs b/crates/ide/src/syntax_highlighting/inject.rs
index 00493a6b5..8e0940184 100644
--- a/crates/ide/src/syntax_highlighting/inject.rs
+++ b/crates/ide/src/syntax_highlighting/inject.rs
@@ -23,7 +23,7 @@ pub(super) fn ra_fixture(
     expanded: SyntaxToken,
 ) -> Option<()> {
     let active_parameter = ActiveParameter::at_token(&sema, expanded)?;
-    if !active_parameter.name.starts_with("ra_fixture") {
+    if !active_parameter.ident().map_or(false, |name| name.text().starts_with("ra_fixture")) {
         return None;
     }
     let value = literal.value()?;
diff --git a/crates/ide_completion/src/completions.rs b/crates/ide_completion/src/completions.rs
index 09882c4f3..cdac4e41a 100644
--- a/crates/ide_completion/src/completions.rs
+++ b/crates/ide_completion/src/completions.rs
@@ -2,25 +2,27 @@
 
 pub(crate) mod attribute;
 pub(crate) mod dot;
-pub(crate) mod record;
-pub(crate) mod pattern;
+pub(crate) mod flyimport;
 pub(crate) mod fn_param;
 pub(crate) mod keyword;
-pub(crate) mod snippet;
-pub(crate) mod qualified_path;
-pub(crate) mod unqualified_path;
-pub(crate) mod postfix;
+pub(crate) mod lifetime;
 pub(crate) mod macro_in_item_position;
-pub(crate) mod trait_impl;
 pub(crate) mod mod_;
-pub(crate) mod flyimport;
+pub(crate) mod pattern;
+pub(crate) mod postfix;
+pub(crate) mod qualified_path;
+pub(crate) mod record;
+pub(crate) mod snippet;
+pub(crate) mod trait_impl;
+pub(crate) mod unqualified_path;
 
 use std::iter;
 
 use hir::{known, ModPath, ScopeDef, Type};
+use ide_db::SymbolKind;
 
 use crate::{
-    item::Builder,
+    item::{Builder, CompletionKind},
     render::{
         const_::render_const,
         enum_variant::render_variant,
@@ -31,7 +33,7 @@ use crate::{
         type_alias::render_type_alias,
         RenderContext,
     },
-    CompletionContext, CompletionItem,
+    CompletionContext, CompletionItem, CompletionItemKind,
 };
 
 /// Represents an in-progress set of completions being built.
@@ -77,6 +79,13 @@ impl Completions {
         self.add(item);
     }
 
+    pub(crate) fn add_static_lifetime(&mut self, ctx: &CompletionContext) {
+        let mut item =
+            CompletionItem::new(CompletionKind::Reference, ctx.source_range(), "'static");
+        item.kind(CompletionItemKind::SymbolKind(SymbolKind::LifetimeParam));
+        self.add(item.build());
+    }
+
     pub(crate) fn add_resolution(
         &mut self,
         ctx: &CompletionContext,
diff --git a/crates/ide_completion/src/completions/lifetime.rs b/crates/ide_completion/src/completions/lifetime.rs
new file mode 100644
index 000000000..628c1fb9b
--- /dev/null
+++ b/crates/ide_completion/src/completions/lifetime.rs
@@ -0,0 +1,285 @@
+//! Completes lifetimes and labels.
+use hir::ScopeDef;
+
+use crate::{completions::Completions, context::CompletionContext};
+
+/// Completes lifetimes.
+pub(crate) fn complete_lifetime(acc: &mut Completions, ctx: &CompletionContext) {
+    if !ctx.lifetime_allowed {
+        return;
+    }
+    let param_lifetime = match (
+        &ctx.lifetime_syntax,
+        ctx.lifetime_param_syntax.as_ref().and_then(|lp| lp.lifetime()),
+    ) {
+        (Some(lt), Some(lp)) if lp == lt.clone() => return,
+        (Some(_), Some(lp)) => Some(lp.to_string()),
+        _ => None,
+    };
+
+    ctx.scope.process_all_names(&mut |name, res| {
+        if let ScopeDef::GenericParam(hir::GenericParam::LifetimeParam(_)) = res {
+            if param_lifetime != Some(name.to_string()) {
+                acc.add_resolution(ctx, name.to_string(), &res);
+            }
+        }
+    });
+    if param_lifetime.is_none() {
+        acc.add_static_lifetime(ctx);
+    }
+}
+
+/// Completes labels.
+pub(crate) fn complete_label(acc: &mut Completions, ctx: &CompletionContext) {
+    if !ctx.is_label_ref {
+        return;
+    }
+    ctx.scope.process_all_names(&mut |name, res| {
+        if let ScopeDef::Label(_) = res {
+            acc.add_resolution(ctx, name.to_string(), &res);
+        }
+    });
+}
+
+#[cfg(test)]
+mod tests {
+    use expect_test::{expect, Expect};
+
+    use crate::{
+        test_utils::{check_edit, completion_list_with_config, TEST_CONFIG},
+        CompletionConfig, CompletionKind,
+    };
+
+    fn check(ra_fixture: &str, expect: Expect) {
+        check_with_config(TEST_CONFIG, ra_fixture, expect);
+    }
+
+    fn check_with_config(config: CompletionConfig, ra_fixture: &str, expect: Expect) {
+        let actual = completion_list_with_config(config, ra_fixture, CompletionKind::Reference);
+        expect.assert_eq(&actual)
+    }
+
+    #[test]
+    fn check_lifetime_edit() {
+        check_edit(
+            "'lifetime",
+            r#"
+fn func<'lifetime>(foo: &'li$0) {}
+"#,
+            r#"
+fn func<'lifetime>(foo: &'lifetime) {}
+"#,
+        );
+    }
+
+    #[test]
+    fn complete_lifetime_in_ref() {
+        check(
+            r#"
+fn foo<'lifetime>(foo: &'a$0 usize) {}
+"#,
+            expect![[r#"
+                lt 'lifetime
+                lt 'static
+            "#]],
+        );
+    }
+
+    #[test]
+    fn complete_lifetime_in_ref_missing_ty() {
+        check(
+            r#"
+fn foo<'lifetime>(foo: &'a$0) {}
+"#,
+            expect![[r#"
+                lt 'lifetime
+                lt 'static
+            "#]],
+        );
+    }
+    #[test]
+    fn complete_lifetime_in_self_ref() {
+        check(
+            r#"
+struct Foo;
+impl<'impl> Foo {
+    fn foo<'func>(&'a$0 self) {}
+}
+"#,
+            expect![[r#"
+                lt 'func
+                lt 'impl
+                lt 'static
+            "#]],
+        );
+    }
+
+    #[test]
+    fn complete_lifetime_in_arg_list() {
+        check(
+            r#"
+struct Foo<'lt>;
+fn foo<'lifetime>(_: Foo<'a$0>) {}
+"#,
+            expect![[r#"
+                lt 'lifetime
+                lt 'static
+            "#]],
+        );
+    }
+
+    #[test]
+    fn complete_lifetime_in_where_pred() {
+        check(
+            r#"
+fn foo2<'lifetime, T>() where 'a$0 {}
+"#,
+            expect![[r#"
+                lt 'lifetime
+                lt 'static
+            "#]],
+        );
+    }
+
+    #[test]
+    fn complete_lifetime_in_ty_bound() {
+        check(
+            r#"
+fn foo2<'lifetime, T>() where T: 'a$0 {}
+"#,
+            expect![[r#"
+                lt 'lifetime
+                lt 'static
+            "#]],
+        );
+        check(
+            r#"
+fn foo2<'lifetime, T>() where T: Trait<'a$0> {}
+"#,
+            expect![[r#"
+                lt 'lifetime
+                lt 'static
+            "#]],
+        );
+    }
+
+    #[test]
+    fn dont_complete_lifetime_in_assoc_ty_bound() {
+        check(
+            r#"
+fn foo2<'lifetime, T>() where T: Trait<Item = 'a$0> {}
+"#,
+            expect![[r#""#]],
+        );
+    }
+
+    #[test]
+    fn complete_lifetime_in_param_list() {
+        check(
+            r#"
+fn foo<'a$0>() {}
+"#,
+            expect![[r#""#]],
+        );
+        check(
+            r#"
+fn foo<'footime, 'lifetime: 'a$0>() {}
+"#,
+            expect![[r#"
+                lt 'footime
+            "#]],
+        );
+    }
+
+    #[test]
+    fn complete_label_in_loop() {
+        check(
+            r#"
+fn foo() {
+    'foop: loop {
+        break '$0
+    }
+}
+"#,
+            expect![[r#"
+                lb 'foop
+            "#]],
+        );
+        check(
+            r#"
+fn foo() {
+    'foop: loop {
+        continue '$0
+    }
+}
+"#,
+            expect![[r#"
+                lb 'foop
+            "#]],
+        );
+    }
+
+    #[test]
+    fn complete_label_in_block_nested() {
+        check(
+            r#"
+fn foo() {
+    'foop: {
+        'baap: {
+            break '$0
+        }
+    }
+}
+"#,
+            expect![[r#"
+                lb 'baap
+                lb 'foop
+            "#]],
+        );
+    }
+
+    #[test]
+    fn complete_label_in_loop_with_value() {
+        check(
+            r#"
+fn foo() {
+    'foop: loop {
+        break '$0 i32;
+    }
+}
+"#,
+            expect![[r#"
+                lb 'foop
+            "#]],
+        );
+    }
+
+    #[test]
+    fn complete_label_in_while_cond() {
+        check(
+            r#"
+fn foo() {
+    'outer: while { 'inner: loop { break '$0 } } {}
+}
+"#,
+            expect![[r#"
+                lb 'inner
+                lb 'outer
+            "#]],
+        );
+    }
+
+    #[test]
+    fn complete_label_in_for_iterable() {
+        check(
+            r#"
+fn foo() {
+    'outer: for _ in [{ 'inner: loop { break '$0 } }] {}
+}
+"#,
+            expect![[r#"
+                lb 'inner
+            "#]],
+        );
+    }
+}
diff --git a/crates/ide_completion/src/completions/pattern.rs b/crates/ide_completion/src/completions/pattern.rs
index 476eecff0..b06498e6d 100644
--- a/crates/ide_completion/src/completions/pattern.rs
+++ b/crates/ide_completion/src/completions/pattern.rs
@@ -1,4 +1,4 @@
-//! Completes constats and paths in patterns.
+//! Completes constants and paths in patterns.
 
 use crate::{CompletionContext, Completions};
 
diff --git a/crates/ide_completion/src/context.rs b/crates/ide_completion/src/context.rs
index 6d57da06a..67e2d6f6c 100644
--- a/crates/ide_completion/src/context.rs
+++ b/crates/ide_completion/src/context.rs
@@ -4,8 +4,11 @@ use hir::{Local, ScopeDef, Semantics, SemanticsScope, Type};
 use ide_db::base_db::{FilePosition, SourceDatabase};
 use ide_db::{call_info::ActiveParameter, RootDatabase};
 use syntax::{
-    algo::find_node_at_offset, ast, match_ast, AstNode, NodeOrToken, SyntaxKind::*, SyntaxNode,
-    SyntaxToken, TextRange, TextSize,
+    algo::find_node_at_offset,
+    ast::{self, NameOrNameRef, NameOwner},
+    match_ast, AstNode, NodeOrToken,
+    SyntaxKind::*,
+    SyntaxNode, SyntaxToken, TextRange, TextSize,
 };
 
 use text_edit::Indel;
@@ -35,18 +38,22 @@ pub(crate) struct CompletionContext<'a> {
     /// The token before the cursor, in the macro-expanded file.
     pub(super) token: SyntaxToken,
     pub(super) krate: Option<hir::Crate>,
-    pub(super) expected_name: Option<String>,
+    pub(super) expected_name: Option<NameOrNameRef>,
     pub(super) expected_type: Option<Type>,
     pub(super) name_ref_syntax: Option<ast::NameRef>,
+    pub(super) lifetime_syntax: Option<ast::Lifetime>,
+    pub(super) lifetime_param_syntax: Option<ast::LifetimeParam>,
     pub(super) function_syntax: Option<ast::Fn>,
     pub(super) use_item_syntax: Option<ast::Use>,
     pub(super) record_lit_syntax: Option<ast::RecordExpr>,
     pub(super) record_pat_syntax: Option<ast::RecordPat>,
     pub(super) record_field_syntax: Option<ast::RecordExprField>,
     pub(super) impl_def: Option<ast::Impl>,
+    pub(super) lifetime_allowed: bool,
     /// FIXME: `ActiveParameter` is string-based, which is very very wrong
     pub(super) active_parameter: Option<ActiveParameter>,
     pub(super) is_param: bool,
+    pub(super) is_label_ref: bool,
     /// If a name-binding or reference to a const in a pattern.
     /// Irrefutable patterns (like let) are excluded.
     pub(super) is_pat_binding_or_const: bool,
@@ -136,9 +143,12 @@ impl<'a> CompletionContext<'a> {
             original_token,
             token,
             krate,
+            lifetime_allowed: false,
             expected_name: None,
             expected_type: None,
             name_ref_syntax: None,
+            lifetime_syntax: None,
+            lifetime_param_syntax: None,
             function_syntax: None,
             use_item_syntax: None,
             record_lit_syntax: None,
@@ -146,6 +156,7 @@ impl<'a> CompletionContext<'a> {
             record_field_syntax: None,
             impl_def: None,
             active_parameter: ActiveParameter::at(db, position),
+            is_label_ref: false,
             is_param: false,
             is_pat_binding_or_const: false,
             is_irrefutable_pat_binding: false,
@@ -241,7 +252,7 @@ impl<'a> CompletionContext<'a> {
     pub(crate) fn source_range(&self) -> TextRange {
         // check kind of macro-expanded token, but use range of original token
         let kind = self.token.kind();
-        if kind == IDENT || kind == UNDERSCORE || kind.is_keyword() {
+        if kind == IDENT || kind == LIFETIME_IDENT || kind == UNDERSCORE || kind.is_keyword() {
             cov_mark::hit!(completes_if_prefix_is_keyword);
             self.original_token.text_range()
         } else {
@@ -292,13 +303,13 @@ impl<'a> CompletionContext<'a> {
         file_with_fake_ident: SyntaxNode,
         offset: TextSize,
     ) {
-        let expected = {
+        let (expected_type, expected_name) = {
             let mut node = match self.token.parent() {
                 Some(it) => it,
                 None => return,
             };
             loop {
-                let ret = match_ast! {
+                break match_ast! {
                     match node {
                         ast::LetStmt(it) => {
                             cov_mark::hit!(expected_type_let_with_leading_char);
@@ -306,7 +317,7 @@ impl<'a> CompletionContext<'a> {
                             let ty = it.pat()
                                 .and_then(|pat| self.sema.type_of_pat(&pat));
                             let name = if let Some(ast::Pat::IdentPat(ident)) = it.pat() {
-                                Some(ident.syntax().text().to_string())
+                                ident.name().map(NameOrNameRef::Name)
                             } else {
                                 None
                             };
@@ -319,7 +330,10 @@ impl<'a> CompletionContext<'a> {
                             ActiveParameter::at_token(
                                 &self.sema,
                                 self.token.clone(),
-                            ).map(|ap| (Some(ap.ty), Some(ap.name)))
+                            ).map(|ap| {
+                                let name = ap.ident().map(NameOrNameRef::Name);
+                                (Some(ap.ty), name)
+                            })
                             .unwrap_or((None, None))
                         },
                         ast::RecordExprFieldList(_it) => {
@@ -327,10 +341,10 @@ impl<'a> CompletionContext<'a> {
                             self.token.prev_sibling_or_token()
                                 .and_then(|se| se.into_node())
                                 .and_then(|node| ast::RecordExprField::cast(node))
-                                .and_then(|rf| self.sema.resolve_record_field(&rf))
-                                .map(|f|(
+                                .and_then(|rf| self.sema.resolve_record_field(&rf).zip(Some(rf)))
+                                .map(|(f, rf)|(
                                     Some(f.0.signature_ty(self.db)),
-                                    Some(f.0.name(self.db).to_string()),
+                                    rf.field_name().map(NameOrNameRef::NameRef),
                                 ))
                                 .unwrap_or((None, None))
                         },
@@ -340,7 +354,7 @@ impl<'a> CompletionContext<'a> {
                                 .resolve_record_field(&it)
                                 .map(|f|(
                                     Some(f.0.signature_ty(self.db)),
-                                    Some(f.0.name(self.db).to_string()),
+                                    it.field_name().map(NameOrNameRef::NameRef),
                                 ))
                                 .unwrap_or((None, None))
                         },
@@ -378,14 +392,17 @@ impl<'a> CompletionContext<'a> {
                         },
                     }
                 };
-
-                break ret;
             }
         };
-        self.expected_type = expected.0;
-        self.expected_name = expected.1;
+        self.expected_type = expected_type;
+        self.expected_name = expected_name;
         self.attribute_under_caret = find_node_at_offset(&file_with_fake_ident, offset);
 
+        if let Some(lifetime) = find_node_at_offset::<ast::Lifetime>(&file_with_fake_ident, offset)
+        {
+            self.classify_lifetime(original_file, lifetime, offset);
+        }
+
         // First, let's try to complete a reference to some declaration.
         if let Some(name_ref) = find_node_at_offset::<ast::NameRef>(&file_with_fake_ident, offset) {
             // Special case, `trait T { fn foo(i_am_a_name_ref) {} }`.
@@ -445,6 +462,35 @@ impl<'a> CompletionContext<'a> {
         }
     }
 
+    fn classify_lifetime(
+        &mut self,
+        original_file: &SyntaxNode,
+        lifetime: ast::Lifetime,
+        offset: TextSize,
+    ) {
+        self.lifetime_syntax =
+            find_node_at_offset(original_file, lifetime.syntax().text_range().start());
+        if let Some(parent) = lifetime.syntax().parent() {
+            if parent.kind() == syntax::SyntaxKind::ERROR {
+                return;
+            }
+
+            match_ast! {
+                match parent {
+                    ast::LifetimeParam(_it) => {
+                        self.lifetime_allowed = true;
+                        self.lifetime_param_syntax =
+                            self.sema.find_node_at_offset_with_macros(original_file, offset);
+                    },
+                    ast::BreakExpr(_it) => self.is_label_ref = true,
+                    ast::ContinueExpr(_it) => self.is_label_ref = true,
+                    ast::Label(_it) => (),
+                    _ => self.lifetime_allowed = true,
+                }
+            }
+        }
+    }
+
     fn classify_name_ref(
         &mut self,
         original_file: &SyntaxNode,
@@ -452,11 +498,11 @@ impl<'a> CompletionContext<'a> {
         offset: TextSize,
     ) {
         self.name_ref_syntax =
-            find_node_at_offset(&original_file, name_ref.syntax().text_range().start());
+            find_node_at_offset(original_file, name_ref.syntax().text_range().start());
         let name_range = name_ref.syntax().text_range();
         if ast::RecordExprField::for_field_name(&name_ref).is_some() {
             self.record_lit_syntax =
-                self.sema.find_node_at_offset_with_macros(&original_file, offset);
+                self.sema.find_node_at_offset_with_macros(original_file, offset);
         }
 
         self.fill_impl_def();
@@ -631,7 +677,9 @@ mod tests {
             .map(|t| t.display_test(&db).to_string())
             .unwrap_or("?".to_owned());
 
-        let name = completion_context.expected_name.unwrap_or("?".to_owned());
+        let name = completion_context
+            .expected_name
+            .map_or_else(|| "?".to_owned(), |name| name.to_string());
 
         expect.assert_eq(&format!("ty: {}, name: {}", ty, name));
     }
diff --git a/crates/ide_completion/src/lib.rs b/crates/ide_completion/src/lib.rs
index 9ecd82b06..87cddb98e 100644
--- a/crates/ide_completion/src/lib.rs
+++ b/crates/ide_completion/src/lib.rs
@@ -133,6 +133,8 @@ pub fn completions(
     completions::trait_impl::complete_trait_impl(&mut acc, &ctx);
     completions::mod_::complete_mod(&mut acc, &ctx);
     completions::flyimport::import_on_the_fly(&mut acc, &ctx);
+    completions::lifetime::complete_lifetime(&mut acc, &ctx);
+    completions::lifetime::complete_label(&mut acc, &ctx);
 
     Some(acc)
 }
diff --git a/crates/ide_completion/src/render.rs b/crates/ide_completion/src/render.rs
index 12921e12b..23e00aa47 100644
--- a/crates/ide_completion/src/render.rs
+++ b/crates/ide_completion/src/render.rs
@@ -219,6 +219,7 @@ impl<'a> Render<'a> {
                 hir::GenericParam::ConstParam(_) => SymbolKind::ConstParam,
             }),
             ScopeDef::Local(..) => CompletionItemKind::SymbolKind(SymbolKind::Local),
+            ScopeDef::Label(..) => CompletionItemKind::SymbolKind(SymbolKind::Label),
             ScopeDef::AdtSelfType(..) | ScopeDef::ImplSelfType(..) => {
                 CompletionItemKind::SymbolKind(SymbolKind::SelfParam)
             }
@@ -243,7 +244,7 @@ impl<'a> Render<'a> {
 
             item.set_relevance(CompletionRelevance {
                 exact_type_match: compute_exact_type_match(self.ctx.completion, &ty),
-                exact_name_match: compute_exact_name_match(self.ctx.completion, local_name.clone()),
+                exact_name_match: compute_exact_name_match(self.ctx.completion, &local_name),
                 is_local: true,
                 ..CompletionRelevance::default()
             });
@@ -319,8 +320,7 @@ fn compute_exact_type_match(ctx: &CompletionContext, completion_ty: &hir::Type)
 
 fn compute_exact_name_match(ctx: &CompletionContext, completion_name: impl Into<String>) -> bool {
     let completion_name = completion_name.into();
-
-    Some(&completion_name) == ctx.expected_name.as_ref()
+    ctx.expected_name.as_ref().map_or(false, |name| name.text() == completion_name)
 }
 
 fn compute_ref_match(ctx: &CompletionContext, completion_ty: &hir::Type) -> Option<Mutability> {
diff --git a/crates/ide_db/src/call_info.rs b/crates/ide_db/src/call_info.rs
index 7e26c3ccf..e583a52f4 100644
--- a/crates/ide_db/src/call_info.rs
+++ b/crates/ide_db/src/call_info.rs
@@ -4,7 +4,7 @@ use either::Either;
 use hir::{HasAttrs, HirDisplay, Semantics, Type};
 use stdx::format_to;
 use syntax::{
-    ast::{self, ArgListOwner},
+    ast::{self, ArgListOwner, NameOwner},
     match_ast, AstNode, SyntaxNode, SyntaxToken, TextRange, TextSize,
 };
 
@@ -142,7 +142,7 @@ fn call_info_impl(
 #[derive(Debug)]
 pub struct ActiveParameter {
     pub ty: Type,
-    pub name: String,
+    pub pat: Either<ast::SelfParam, ast::Pat>,
 }
 
 impl ActiveParameter {
@@ -165,8 +165,14 @@ impl ActiveParameter {
             return None;
         }
         let (pat, ty) = params.swap_remove(idx);
-        let name = pat?.to_string();
-        Some(ActiveParameter { ty, name })
+        pat.map(|pat| ActiveParameter { ty, pat })
+    }
+
+    pub fn ident(&self) -> Option<ast::Name> {
+        self.pat.as_ref().right().and_then(|param| match param {
+            ast::Pat::IdentPat(ident) => ident.name(),
+            _ => None,
+        })
     }
 }
 
diff --git a/crates/mbe/src/expander/matcher.rs b/crates/mbe/src/expander/matcher.rs
index b6782b4ba..1682b21b0 100644
--- a/crates/mbe/src/expander/matcher.rs
+++ b/crates/mbe/src/expander/matcher.rs
@@ -762,7 +762,7 @@ impl<'a> TtIter<'a> {
     fn expect_separator(&mut self, separator: &Separator, idx: usize) -> bool {
         let mut fork = self.clone();
         let ok = match separator {
-            Separator::Ident(lhs) if idx == 0 => match fork.expect_ident() {
+            Separator::Ident(lhs) if idx == 0 => match fork.expect_ident_or_underscore() {
                 Ok(rhs) => rhs.text == lhs.text,
                 _ => false,
             },
@@ -852,7 +852,7 @@ impl<'a> TtIter<'a> {
         if punct.char != '\'' {
             return Err(());
         }
-        let ident = self.expect_ident()?;
+        let ident = self.expect_ident_or_underscore()?;
 
         Ok(tt::Subtree {
             delimiter: None,
diff --git a/crates/mbe/src/parser.rs b/crates/mbe/src/parser.rs
index 7b5b8ec16..c88387653 100644
--- a/crates/mbe/src/parser.rs
+++ b/crates/mbe/src/parser.rs
@@ -177,16 +177,8 @@ fn next_op<'a>(first: &tt::TokenTree, src: &mut TtIter<'a>, mode: Mode) -> Resul
                     Op::Repeat { tokens: MetaTemplate(tokens), separator, kind }
                 }
                 tt::TokenTree::Leaf(leaf) => match leaf {
-                    tt::Leaf::Punct(punct) => {
-                        static UNDERSCORE: SmolStr = SmolStr::new_inline("_");
-
-                        if punct.char != '_' {
-                            return Err(ParseError::Expected("_".to_string()));
-                        }
-                        let name = UNDERSCORE.clone();
-                        let kind = eat_fragment_kind(src, mode)?;
-                        let id = punct.id;
-                        Op::Var { name, kind, id }
+                    tt::Leaf::Punct(_) => {
+                        return Err(ParseError::Expected("ident".to_string()));
                     }
                     tt::Leaf::Ident(ident) if ident.text == "crate" => {
                         // We simply produce identifier `$crate` here. And it will be resolved when lowering ast to Path.
diff --git a/crates/mbe/src/subtree_source.rs b/crates/mbe/src/subtree_source.rs
index d7433bd35..a05cab0f3 100644
--- a/crates/mbe/src/subtree_source.rs
+++ b/crates/mbe/src/subtree_source.rs
@@ -150,6 +150,7 @@ fn convert_ident(ident: &tt::Ident) -> TtToken {
     let kind = match ident.text.as_ref() {
         "true" => T![true],
         "false" => T![false],
+        "_" => UNDERSCORE,
         i if i.starts_with('\'') => LIFETIME_IDENT,
         _ => SyntaxKind::from_keyword(ident.text.as_str()).unwrap_or(IDENT),
     };
diff --git a/crates/mbe/src/syntax_bridge.rs b/crates/mbe/src/syntax_bridge.rs
index 85163c4b3..8bba3d3d5 100644
--- a/crates/mbe/src/syntax_bridge.rs
+++ b/crates/mbe/src/syntax_bridge.rs
@@ -350,7 +350,7 @@ trait TokenConvertor {
             return;
         }
 
-        result.push(if k.is_punct() {
+        result.push(if k.is_punct() && k != UNDERSCORE {
             assert_eq!(range.len(), TextSize::of('.'));
             let delim = match k {
                 T!['('] => Some((tt::DelimiterKind::Parenthesis, T![')'])),
@@ -395,7 +395,9 @@ trait TokenConvertor {
                     {
                         tt::Spacing::Alone
                     }
-                    Some(next) if next.kind().is_punct() => tt::Spacing::Joint,
+                    Some(next) if next.kind().is_punct() && next.kind() != UNDERSCORE => {
+                        tt::Spacing::Joint
+                    }
                     _ => tt::Spacing::Alone,
                 };
                 let char = match token.to_char() {
@@ -415,6 +417,7 @@ trait TokenConvertor {
             let leaf: tt::Leaf = match k {
                 T![true] | T![false] => make_leaf!(Ident),
                 IDENT => make_leaf!(Ident),
+                UNDERSCORE => make_leaf!(Ident),
                 k if k.is_keyword() => make_leaf!(Ident),
                 k if k.is_literal() => make_leaf!(Literal),
                 LIFETIME_IDENT => {
diff --git a/crates/mbe/src/tests/expand.rs b/crates/mbe/src/tests/expand.rs
index 9dd8ff75b..2cce62781 100644
--- a/crates/mbe/src/tests/expand.rs
+++ b/crates/mbe/src/tests/expand.rs
@@ -1080,6 +1080,12 @@ macro_rules! q {
 }
 
 #[test]
+fn test_underscore_lifetime() {
+    parse_macro(r#"macro_rules! q { ($a:lifetime) => {0}; }"#)
+        .assert_expand_items(r#"q!['_]"#, r#"0"#);
+}
+
+#[test]
 fn test_vertical_bar_with_pat() {
     parse_macro(
         r#"
diff --git a/crates/mbe/src/tests/rule.rs b/crates/mbe/src/tests/rule.rs
index 07277966d..bf48112b3 100644
--- a/crates/mbe/src/tests/rule.rs
+++ b/crates/mbe/src/tests/rule.rs
@@ -12,6 +12,9 @@ fn test_valid_arms() {
     }
 
     check("($i:ident) => ()");
+    check("($(x),*) => ()");
+    check("($(x)_*) => ()");
+    check("($(x)i*) => ()");
     check("($($i:ident)*) => ($_)");
     check("($($true:ident)*) => ($true)");
     check("($($false:ident)*) => ($false)");
@@ -32,6 +35,7 @@ fn test_invalid_arms() {
 
     check("($i) => ($i)", ParseError::UnexpectedToken("bad fragment specifier 1".into()));
     check("($i:) => ($i)", ParseError::UnexpectedToken("bad fragment specifier 1".into()));
+    check("($i:_) => ()", ParseError::UnexpectedToken("bad fragment specifier 1".into()));
 }
 
 fn parse_macro_arm(arm_definition: &str) -> Result<crate::MacroRules, ParseError> {
diff --git a/crates/mbe/src/tt_iter.rs b/crates/mbe/src/tt_iter.rs
index a362d31fc..319a40f2a 100644
--- a/crates/mbe/src/tt_iter.rs
+++ b/crates/mbe/src/tt_iter.rs
@@ -50,6 +50,13 @@ impl<'a> TtIter<'a> {
 
     pub(crate) fn expect_ident(&mut self) -> Result<&'a tt::Ident, ()> {
         match self.expect_leaf()? {
+            tt::Leaf::Ident(it) if it.text != "_" => Ok(it),
+            _ => Err(()),
+        }
+    }
+
+    pub(crate) fn expect_ident_or_underscore(&mut self) -> Result<&'a tt::Ident, ()> {
+        match self.expect_leaf()? {
             tt::Leaf::Ident(it) => Ok(it),
             _ => Err(()),
         }
diff --git a/crates/proc_macro_srv/src/rustc_server.rs b/crates/proc_macro_srv/src/rustc_server.rs
index ceefd187d..c147484c0 100644
--- a/crates/proc_macro_srv/src/rustc_server.rs
+++ b/crates/proc_macro_srv/src/rustc_server.rs
@@ -805,5 +805,14 @@ mod tests {
         let t2 = TokenStream::from_str("(a);").unwrap();
         assert_eq!(t2.token_trees.len(), 2);
         assert_eq!(t2.token_trees[0], subtree_paren_a);
+
+        let underscore = TokenStream::from_str("_").unwrap();
+        assert_eq!(
+            underscore.token_trees[0],
+            tt::TokenTree::Leaf(tt::Leaf::Ident(tt::Ident {
+                text: "_".into(),
+                id: tt::TokenId::unspecified(),
+            }))
+        );
     }
 }
diff --git a/crates/syntax/src/ast/node_ext.rs b/crates/syntax/src/ast/node_ext.rs
index 01f580a40..42a7b9c2a 100644
--- a/crates/syntax/src/ast/node_ext.rs
+++ b/crates/syntax/src/ast/node_ext.rs
@@ -380,6 +380,15 @@ impl fmt::Display for NameOrNameRef {
     }
 }
 
+impl NameOrNameRef {
+    pub fn text(&self) -> &str {
+        match self {
+            NameOrNameRef::Name(name) => name.text(),
+            NameOrNameRef::NameRef(name_ref) => name_ref.text(),
+        }
+    }
+}
+
 impl ast::RecordPatField {
     pub fn for_field_name_ref(field_name: &ast::NameRef) -> Option<ast::RecordPatField> {
         let candidate = field_name.syntax().parent().and_then(ast::RecordPatField::cast)?;