20 files changed, 399 insertions, 151 deletions

diff --git a/Cargo.lock b/Cargo.lock
index 57383491a..bc38c5a37 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -262,9 +262,9 @@ dependencies = [
 
 [[package]]
 name = "const_fn"
-version = "0.4.4"
+version = "0.4.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "cd51eab21ab4fd6a3bf889e2d0958c0a6e3a61ad04260325e919e652a2a62826"
+checksum = "28b9d6de7f49e22cf97ad17fc4036ece69300032f45f78f30b4a4482cdc3f4a6"
 
 [[package]]
 name = "crc32fast"
@@ -774,9 +774,9 @@ checksum = "830d08ce1d1d941e6b30645f1a0eb5643013d835ce3779a5fc208261dbe10f55"
 
 [[package]]
 name = "libc"
-version = "0.2.81"
+version = "0.2.82"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1482821306169ec4d07f6aca392a4681f66c75c9918aa49641a2595db64053cb"
+checksum = "89203f3fba0a3795506acaad8ebce3c80c0af93f994d5a1d7a0b1eeb23271929"
 
 [[package]]
 name = "libloading"
@@ -1134,9 +1134,9 @@ checksum = "28b9b4df73455c861d7cbf8be42f01d3b373ed7f02e378d55fa84eafc6f638b1"
 
 [[package]]
 name = "pin-project-lite"
-version = "0.2.0"
+version = "0.2.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6b063f57ec186e6140e2b8b6921e5f1bd89c7356dda5b33acc5401203ca6131c"
+checksum = "e36743d754ccdf9954c2e352ce2d4b106e024c814f6499c2dadff80da9a442d8"
 
 [[package]]
 name = "proc-macro2"
@@ -1449,9 +1449,9 @@ dependencies = [
 
 [[package]]
 name = "semver-parser"
-version = "0.10.1"
+version = "0.10.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "42ef146c2ad5e5f4b037cd6ce2ebb775401729b19a82040c1beac9d36c7d1428"
+checksum = "00b0bef5b7f9e0df16536d3961cfb6e84331c065b4066afb39768d0e319411f7"
 dependencies = [
  "pest",
 ]
@@ -1558,9 +1558,9 @@ version = "0.0.0"
 
 [[package]]
 name = "syn"
-version = "1.0.57"
+version = "1.0.58"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4211ce9909eb971f111059df92c45640aad50a619cf55cd76476be803c4c68e6"
+checksum = "cc60a3d73ea6594cd712d830cc1f0390fd71542d8c8cd24e70cc54cdfd5e05d5"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -1643,9 +1643,9 @@ checksum = "db3c46be180f1af9673ebb27bc1235396f61ef6965b3fe0dbb2e624deb604f0e"
 
 [[package]]
 name = "thread_local"
-version = "1.0.1"
+version = "1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d40c6d1b69745a6ec6fb1ca717914848da4b44ae29d9b3080cbee91d72a69b14"
+checksum = "bb9bc092d0d51e76b2b19d9d85534ffc9ec2db959a2523cdae0697e2972cd447"
 dependencies = [
  "lazy_static",
 ]
diff --git a/crates/completion/src/completions/attribute.rs b/crates/completion/src/completions/attribute.rs
index 10739750c..3a29b5203 100644
--- a/crates/completion/src/completions/attribute.rs
+++ b/crates/completion/src/completions/attribute.rs
@@ -21,20 +21,15 @@ pub(crate) fn complete_attribute(acc: &mut Completions, ctx: &CompletionContext)
 
     let attribute = ctx.attribute_under_caret.as_ref()?;
     match (attribute.path(), attribute.token_tree()) {
-        (Some(path), Some(token_tree)) if path.to_string() == "derive" => {
-            complete_derive(acc, ctx, token_tree)
-        }
-        (Some(path), Some(token_tree)) if path.to_string() == "feature" => {
-            complete_lint(acc, ctx, token_tree, FEATURES);
-        }
-        (Some(path), Some(token_tree))
-            if ["allow", "warn", "deny", "forbid"]
-                .iter()
-                .any(|lint_level| lint_level == &path.to_string()) =>
-        {
-            complete_lint(acc, ctx, token_tree.clone(), DEFAULT_LINT_COMPLETIONS);
-            complete_lint(acc, ctx, token_tree, CLIPPY_LINTS);
-        }
+        (Some(path), Some(token_tree)) => match path.to_string().as_str() {
+            "derive" => complete_derive(acc, ctx, token_tree),
+            "feature" => complete_lint(acc, ctx, token_tree, FEATURES),
+            "allow" | "warn" | "deny" | "forbid" => {
+                complete_lint(acc, ctx, token_tree.clone(), DEFAULT_LINT_COMPLETIONS);
+                complete_lint(acc, ctx, token_tree, CLIPPY_LINTS);
+            }
+            _ => {}
+        },
         (_, Some(_token_tree)) => {}
         _ => complete_attribute_start(acc, ctx, attribute),
     }
@@ -54,11 +49,8 @@ fn complete_attribute_start(acc: &mut Completions, ctx: &CompletionContext, attr
             item = item.lookup_by(lookup);
         }
 
-        match (attr_completion.snippet, ctx.config.snippet_cap) {
-            (Some(snippet), Some(cap)) => {
-                item = item.insert_snippet(cap, snippet);
-            }
-            _ => {}
+        if let Some((snippet, cap)) = attr_completion.snippet.zip(ctx.config.snippet_cap) {
+            item = item.insert_snippet(cap, snippet);
         }
 
         if attribute.kind() == ast::AttrKind::Inner || !attr_completion.prefer_inner {
diff --git a/crates/completion/src/completions/mod_.rs b/crates/completion/src/completions/mod_.rs
index 8c8eaeaa6..00e951ca9 100644
--- a/crates/completion/src/completions/mod_.rs
+++ b/crates/completion/src/completions/mod_.rs
@@ -1,5 +1,7 @@
 //! Completes mod declarations.
 
+use std::iter;
+
 use hir::{Module, ModuleSource};
 use ide_db::base_db::{SourceDatabaseExt, VfsPath};
 use ide_db::RootDatabase;
@@ -12,9 +14,8 @@ use crate::{context::CompletionContext, item::CompletionKind, Completions};
 /// Complete mod declaration, i.e. `mod $0 ;`
 pub(crate) fn complete_mod(acc: &mut Completions, ctx: &CompletionContext) -> Option<()> {
     let mod_under_caret = match &ctx.mod_declaration_under_caret {
-        Some(mod_under_caret) if mod_under_caret.item_list().is_some() => return None,
-        Some(mod_under_caret) => mod_under_caret,
-        None => return None,
+        Some(mod_under_caret) if mod_under_caret.item_list().is_none() => mod_under_caret,
+        _ => return None,
     };
 
     let _p = profile::span("completion::complete_mod");
@@ -49,9 +50,13 @@ pub(crate) fn complete_mod(acc: &mut Completions, ctx: &CompletionContext) -> Op
         .filter_map(|submodule_file| {
             let submodule_path = source_root.path_for_file(&submodule_file)?;
             let directory_with_submodule = submodule_path.parent()?;
-            match submodule_path.name_and_extension()? {
-                ("lib", Some("rs")) | ("main", Some("rs")) => None,
-                ("mod", Some("rs")) => {
+            let (name, ext) = submodule_path.name_and_extension()?;
+            if ext != Some("rs") {
+                return None;
+            }
+            match name {
+                "lib" | "main" => None,
+                "mod" => {
                     if directory_with_submodule.parent()? == directory_to_look_for_submodules {
                         match directory_with_submodule.name_and_extension()? {
                             (directory_name, None) => Some(directory_name.to_owned()),
@@ -61,9 +66,7 @@ pub(crate) fn complete_mod(acc: &mut Completions, ctx: &CompletionContext) -> Op
                         None
                     }
                 }
-                (file_name, Some("rs"))
-                    if directory_with_submodule == directory_to_look_for_submodules =>
-                {
+                file_name if directory_with_submodule == directory_to_look_for_submodules => {
                     Some(file_name.to_owned())
                 }
                 _ => None,
@@ -73,7 +76,7 @@ pub(crate) fn complete_mod(acc: &mut Completions, ctx: &CompletionContext) -> Op
         .for_each(|submodule_name| {
             let mut label = submodule_name;
             if mod_under_caret.semicolon_token().is_none() {
-                label.push(';')
+                label.push(';');
             }
             CompletionItem::new(CompletionKind::Magic, ctx.source_range(), &label)
                 .kind(CompletionItemKind::Module)
@@ -89,11 +92,13 @@ fn directory_to_look_for_submodules(
     module_file_path: &VfsPath,
 ) -> Option<VfsPath> {
     let directory_with_module_path = module_file_path.parent()?;
-    let base_directory = match module_file_path.name_and_extension()? {
-        ("mod", Some("rs")) | ("lib", Some("rs")) | ("main", Some("rs")) => {
-            Some(directory_with_module_path)
-        }
-        (regular_rust_file_name, Some("rs")) => {
+    let (name, ext) = module_file_path.name_and_extension()?;
+    if ext != Some("rs") {
+        return None;
+    }
+    let base_directory = match name {
+        "mod" | "lib" | "main" => Some(directory_with_module_path),
+        regular_rust_file_name => {
             if matches!(
                 (
                     directory_with_module_path
@@ -110,37 +115,25 @@ fn directory_to_look_for_submodules(
                 directory_with_module_path.join(regular_rust_file_name)
             }
         }
-        _ => None,
     }?;
 
-    let mut resulting_path = base_directory;
-    for module in module_chain_to_containing_module_file(module, db) {
-        if let Some(name) = module.name(db) {
-            resulting_path = resulting_path.join(&name.to_string())?;
-        }
-    }
-
-    Some(resulting_path)
+    module_chain_to_containing_module_file(module, db)
+        .into_iter()
+        .filter_map(|module| module.name(db))
+        .try_fold(base_directory, |path, name| path.join(&name.to_string()))
 }
 
 fn module_chain_to_containing_module_file(
     current_module: Module,
     db: &RootDatabase,
 ) -> Vec<Module> {
-    let mut path = Vec::new();
-
-    let mut current_module = Some(current_module);
-    while let Some(ModuleSource::Module(_)) =
-        current_module.map(|module| module.definition_source(db).value)
-    {
-        if let Some(module) = current_module {
-            path.insert(0, module);
-            current_module = module.parent(db);
-        } else {
-            current_module = None;
-        }
-    }
-
+    let mut path =
+        iter::successors(Some(current_module), |current_module| current_module.parent(db))
+            .take_while(|current_module| {
+                matches!(current_module.definition_source(db).value, ModuleSource::Module(_))
+            })
+            .collect::<Vec<_>>();
+    path.reverse();
     path
 }
 
diff --git a/crates/hir/src/db.rs b/crates/hir/src/db.rs
index d01e1b33d..d5d4cf5b6 100644
--- a/crates/hir/src/db.rs
+++ b/crates/hir/src/db.rs
@@ -10,8 +10,8 @@ pub use hir_def::db::{
     TypeAliasDataQuery, UnionDataQuery,
 };
 pub use hir_expand::db::{
-    AstDatabase, AstDatabaseStorage, AstIdMapQuery, InternEagerExpansionQuery, InternMacroQuery,
-    MacroArgTextQuery, MacroDefQuery, MacroExpandQuery, ParseMacroExpansionQuery,
+    AstDatabase, AstDatabaseStorage, AstIdMapQuery, HygieneFrameQuery, InternEagerExpansionQuery,
+    InternMacroQuery, MacroArgTextQuery, MacroDefQuery, MacroExpandQuery, ParseMacroExpansionQuery,
 };
 pub use hir_ty::db::*;
 
diff --git a/crates/hir/src/diagnostics.rs b/crates/hir/src/diagnostics.rs
index b1c924167..447faa04f 100644
--- a/crates/hir/src/diagnostics.rs
+++ b/crates/hir/src/diagnostics.rs
@@ -4,6 +4,6 @@ pub use hir_expand::diagnostics::{
     Diagnostic, DiagnosticCode, DiagnosticSink, DiagnosticSinkBuilder,
 };
 pub use hir_ty::diagnostics::{
-    IncorrectCase, MismatchedArgCount, MissingFields, MissingMatchArms, MissingOkInTailExpr,
+    IncorrectCase, MismatchedArgCount, MissingFields, MissingMatchArms, MissingOkOrSomeInTailExpr,
     NoSuchField, RemoveThisSemicolon,
 };
diff --git a/crates/hir_def/src/path.rs b/crates/hir_def/src/path.rs
index e2bf85bbc..3dd7c3cbb 100644
--- a/crates/hir_def/src/path.rs
+++ b/crates/hir_def/src/path.rs
@@ -305,6 +305,7 @@ pub use hir_expand::name as __name;
 macro_rules! __known_path {
     (core::iter::IntoIterator) => {};
     (core::result::Result) => {};
+    (core::option::Option) => {};
     (core::ops::Range) => {};
     (core::ops::RangeFrom) => {};
     (core::ops::RangeFull) => {};
diff --git a/crates/hir_def/src/path/lower.rs b/crates/hir_def/src/path/lower.rs
index 8a01e6eea..9518ac109 100644
--- a/crates/hir_def/src/path/lower.rs
+++ b/crates/hir_def/src/path/lower.rs
@@ -123,7 +123,7 @@ pub(super) fn lower_path(mut path: ast::Path, hygiene: &Hygiene) -> Option<Path>
     // We follow what it did anyway :)
     if segments.len() == 1 && kind == PathKind::Plain {
         if let Some(_macro_call) = path.syntax().parent().and_then(ast::MacroCall::cast) {
-            if let Some(crate_id) = hygiene.local_inner_macros() {
+            if let Some(crate_id) = hygiene.local_inner_macros(path) {
                 kind = PathKind::DollarCrate(crate_id);
             }
         }
diff --git a/crates/hir_expand/src/db.rs b/crates/hir_expand/src/db.rs
index 0a0d021e0..ab2637b8c 100644
--- a/crates/hir_expand/src/db.rs
+++ b/crates/hir_expand/src/db.rs
@@ -8,9 +8,9 @@ use parser::FragmentKind;
 use syntax::{algo::diff, ast::NameOwner, AstNode, GreenNode, Parse, SyntaxKind::*, SyntaxNode};
 
 use crate::{
-    ast_id_map::AstIdMap, BuiltinDeriveExpander, BuiltinFnLikeExpander, EagerCallLoc, EagerMacroId,
-    HirFileId, HirFileIdRepr, LazyMacroId, MacroCallId, MacroCallLoc, MacroDefId, MacroDefKind,
-    MacroFile, ProcMacroExpander,
+    ast_id_map::AstIdMap, hygiene::HygieneFrame, BuiltinDeriveExpander, BuiltinFnLikeExpander,
+    EagerCallLoc, EagerMacroId, HirFileId, HirFileIdRepr, LazyMacroId, MacroCallId, MacroCallLoc,
+    MacroDefId, MacroDefKind, MacroFile, ProcMacroExpander,
 };
 
 /// Total limit on the number of tokens produced by any macro invocation.
@@ -94,6 +94,8 @@ pub trait AstDatabase: SourceDatabase {
     fn intern_eager_expansion(&self, eager: EagerCallLoc) -> EagerMacroId;
 
     fn expand_proc_macro(&self, call: MacroCallId) -> Result<tt::Subtree, mbe::ExpandError>;
+
+    fn hygiene_frame(&self, file_id: HirFileId) -> Arc<HygieneFrame>;
 }
 
 /// This expands the given macro call, but with different arguments. This is
@@ -369,6 +371,10 @@ fn parse_macro_with_arg(
     }
 }
 
+fn hygiene_frame(db: &dyn AstDatabase, file_id: HirFileId) -> Arc<HygieneFrame> {
+    Arc::new(HygieneFrame::new(db, file_id))
+}
+
 /// Given a `MacroCallId`, return what `FragmentKind` it belongs to.
 /// FIXME: Not completed
 fn to_fragment_kind(db: &dyn AstDatabase, id: MacroCallId) -> FragmentKind {
diff --git a/crates/hir_expand/src/hygiene.rs b/crates/hir_expand/src/hygiene.rs
index 7ab0a5e52..8db581b77 100644
--- a/crates/hir_expand/src/hygiene.rs
+++ b/crates/hir_expand/src/hygiene.rs
@@ -2,65 +2,209 @@
 //!
 //! Specifically, `ast` + `Hygiene` allows you to create a `Name`. Note that, at
 //! this moment, this is horribly incomplete and handles only `$crate`.
+use std::sync::Arc;
+
 use base_db::CrateId;
 use either::Either;
-use syntax::ast;
+use mbe::Origin;
+use parser::SyntaxKind;
+use syntax::{ast, AstNode, SyntaxNode, TextRange, TextSize};
 
 use crate::{
-    db::AstDatabase,
+    db::{self, AstDatabase},
     name::{AsName, Name},
-    HirFileId, HirFileIdRepr, MacroCallId, MacroDefKind,
+    HirFileId, HirFileIdRepr, InFile, MacroCallId, MacroCallLoc, MacroDefKind, MacroFile,
 };
 
 #[derive(Clone, Debug)]
 pub struct Hygiene {
-    // This is what `$crate` expands to
-    def_crate: Option<CrateId>,
-
-    // Indicate this is a local inner macro
-    local_inner: bool,
+    frames: Option<HygieneFrames>,
 }
 
 impl Hygiene {
     pub fn new(db: &dyn AstDatabase, file_id: HirFileId) -> Hygiene {
-        let (def_crate, local_inner) = match file_id.0 {
-            HirFileIdRepr::FileId(_) => (None, false),
-            HirFileIdRepr::MacroFile(macro_file) => match macro_file.macro_call_id {
-                MacroCallId::LazyMacro(id) => {
-                    let loc = db.lookup_intern_macro(id);
-                    match loc.def.kind {
-                        MacroDefKind::Declarative => (Some(loc.def.krate), loc.def.local_inner),
-                        MacroDefKind::BuiltIn(_) => (Some(loc.def.krate), false),
-                        MacroDefKind::BuiltInDerive(_) => (None, false),
-                        MacroDefKind::BuiltInEager(_) => (None, false),
-                        MacroDefKind::ProcMacro(_) => (None, false),
-                    }
-                }
-                MacroCallId::EagerMacro(_id) => (None, false),
-            },
-        };
-        Hygiene { def_crate, local_inner }
+        Hygiene { frames: Some(HygieneFrames::new(db, file_id.clone())) }
     }
 
     pub fn new_unhygienic() -> Hygiene {
-        Hygiene { def_crate: None, local_inner: false }
+        Hygiene { frames: None }
     }
 
     // FIXME: this should just return name
     pub fn name_ref_to_name(&self, name_ref: ast::NameRef) -> Either<Name, CrateId> {
-        if let Some(def_crate) = self.def_crate {
+        if let Some(frames) = &self.frames {
             if name_ref.text() == "$crate" {
-                return Either::Right(def_crate);
+                if let Some(krate) = frames.root_crate(name_ref.syntax()) {
+                    return Either::Right(krate);
+                }
             }
         }
+
         Either::Left(name_ref.as_name())
     }
 
-    pub fn local_inner_macros(&self) -> Option<CrateId> {
-        if self.local_inner {
-            self.def_crate
-        } else {
-            None
+    pub fn local_inner_macros(&self, path: ast::Path) -> Option<CrateId> {
+        let mut token = path.syntax().first_token()?.text_range();
+        let frames = self.frames.as_ref()?;
+        let mut current = frames.0.clone();
+
+        loop {
+            let (mapped, origin) = current.expansion.as_ref()?.map_ident_up(token)?;
+            if origin == Origin::Def {
+                return if current.local_inner { frames.root_crate(path.syntax()) } else { None };
+            }
+            current = current.call_site.as_ref()?.clone();
+            token = mapped.value;
+        }
+    }
+}
+
+#[derive(Clone, Debug)]
+struct HygieneFrames(Arc<HygieneFrame>);
+
+#[derive(Clone, Debug, Eq, PartialEq)]
+pub struct HygieneFrame {
+    expansion: Option<HygieneInfo>,
+
+    // Indicate this is a local inner macro
+    local_inner: bool,
+    krate: Option<CrateId>,
+
+    call_site: Option<Arc<HygieneFrame>>,
+    def_site: Option<Arc<HygieneFrame>>,
+}
+
+impl HygieneFrames {
+    fn new(db: &dyn AstDatabase, file_id: HirFileId) -> Self {
+        HygieneFrames(Arc::new(HygieneFrame::new(db, file_id)))
+    }
+
+    fn root_crate(&self, node: &SyntaxNode) -> Option<CrateId> {
+        let mut token = node.first_token()?.text_range();
+        let mut result = self.0.krate;
+        let mut current = self.0.clone();
+
+        while let Some((mapped, origin)) =
+            current.expansion.as_ref().and_then(|it| it.map_ident_up(token))
+        {
+            result = current.krate;
+
+            let site = match origin {
+                Origin::Def => &current.def_site,
+                Origin::Call => &current.call_site,
+            };
+
+            let site = match site {
+                None => break,
+                Some(it) => it,
+            };
+
+            current = site.clone();
+            token = mapped.value;
         }
+
+        result
+    }
+}
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+struct HygieneInfo {
+    arg_start: InFile<TextSize>,
+    /// The `macro_rules!` arguments.
+    def_start: Option<InFile<TextSize>>,
+
+    macro_def: Arc<(db::TokenExpander, mbe::TokenMap)>,
+    macro_arg: Arc<(tt::Subtree, mbe::TokenMap)>,
+    exp_map: Arc<mbe::TokenMap>,
+}
+
+impl HygieneInfo {
+    fn map_ident_up(&self, token: TextRange) -> Option<(InFile<TextRange>, Origin)> {
+        let token_id = self.exp_map.token_by_range(token)?;
+
+        let (token_id, origin) = self.macro_def.0.map_id_up(token_id);
+        let (token_map, tt) = match origin {
+            mbe::Origin::Call => (&self.macro_arg.1, self.arg_start),
+            mbe::Origin::Def => (
+                &self.macro_def.1,
+                self.def_start
+                    .as_ref()
+                    .expect("`Origin::Def` used with non-`macro_rules!` macro")
+                    .clone(),
+            ),
+        };
+
+        let range = token_map.range_by_token(token_id)?.by_kind(SyntaxKind::IDENT)?;
+        Some((tt.with_value(range + tt.value), origin))
+    }
+}
+
+fn make_hygiene_info(
+    db: &dyn AstDatabase,
+    macro_file: MacroFile,
+    loc: &MacroCallLoc,
+) -> Option<HygieneInfo> {
+    let arg_tt = loc.kind.arg(db)?;
+
+    let def_offset = loc.def.ast_id.and_then(|id| {
+        let def_tt = match id.to_node(db) {
+            ast::Macro::MacroRules(mac) => mac.token_tree()?.syntax().text_range().start(),
+            ast::Macro::MacroDef(_) => return None,
+        };
+        Some(InFile::new(id.file_id, def_tt))
+    });
+
+    let macro_def = db.macro_def(loc.def)?;
+    let (_, exp_map) = db.parse_macro_expansion(macro_file).value?;
+    let macro_arg = db.macro_arg(macro_file.macro_call_id)?;
+
+    Some(HygieneInfo {
+        arg_start: InFile::new(loc.kind.file_id(), arg_tt.text_range().start()),
+        def_start: def_offset,
+        macro_arg,
+        macro_def,
+        exp_map,
+    })
+}
+
+impl HygieneFrame {
+    pub(crate) fn new(db: &dyn AstDatabase, file_id: HirFileId) -> HygieneFrame {
+        let (info, krate, local_inner) = match file_id.0 {
+            HirFileIdRepr::FileId(_) => (None, None, false),
+            HirFileIdRepr::MacroFile(macro_file) => match macro_file.macro_call_id {
+                MacroCallId::EagerMacro(_id) => (None, None, false),
+                MacroCallId::LazyMacro(id) => {
+                    let loc = db.lookup_intern_macro(id);
+                    let info = make_hygiene_info(db, macro_file, &loc);
+                    match loc.def.kind {
+                        MacroDefKind::Declarative => {
+                            (info, Some(loc.def.krate), loc.def.local_inner)
+                        }
+                        MacroDefKind::BuiltIn(_) => (info, Some(loc.def.krate), false),
+                        MacroDefKind::BuiltInDerive(_) => (info, None, false),
+                        MacroDefKind::BuiltInEager(_) => (info, None, false),
+                        MacroDefKind::ProcMacro(_) => (info, None, false),
+                    }
+                }
+            },
+        };
+
+        let info = match info {
+            None => {
+                return HygieneFrame {
+                    expansion: None,
+                    local_inner,
+                    krate,
+                    call_site: None,
+                    def_site: None,
+                };
+            }
+            Some(it) => it,
+        };
+
+        let def_site = info.def_start.map(|it| db.hygiene_frame(it.file_id));
+        let call_site = Some(db.hygiene_frame(info.arg_start.file_id));
+
+        HygieneFrame { expansion: Some(info), local_inner, krate, call_site, def_site }
     }
 }
diff --git a/crates/hir_expand/src/name.rs b/crates/hir_expand/src/name.rs
index 2f44876a8..95d853b6d 100644
--- a/crates/hir_expand/src/name.rs
+++ b/crates/hir_expand/src/name.rs
@@ -164,6 +164,7 @@ pub mod known {
         future,
         result,
         boxed,
+        option,
         // Components of known path (type name)
         Iterator,
         IntoIterator,
@@ -172,6 +173,7 @@ pub mod known {
         Ok,
         Future,
         Result,
+        Option,
         Output,
         Target,
         Box,
diff --git a/crates/hir_ty/src/diagnostics.rs b/crates/hir_ty/src/diagnostics.rs
index 14e18f5a1..c67a289f2 100644
--- a/crates/hir_ty/src/diagnostics.rs
+++ b/crates/hir_ty/src/diagnostics.rs
@@ -186,9 +186,10 @@ impl Diagnostic for MissingMatchArms {
     }
 }
 
-// Diagnostic: missing-ok-in-tail-expr
+// Diagnostic: missing-ok-or-some-in-tail-expr
 //
-// This diagnostic is triggered if block that should return `Result` returns a value not wrapped in `Ok`.
+// This diagnostic is triggered if a block that should return `Result` returns a value not wrapped in `Ok`,
+// or if a block that should return `Option` returns a value not wrapped in `Some`.
 //
 // Example:
 //
@@ -198,17 +199,19 @@ impl Diagnostic for MissingMatchArms {
 // }
 // ```
 #[derive(Debug)]
-pub struct MissingOkInTailExpr {
+pub struct MissingOkOrSomeInTailExpr {
     pub file: HirFileId,
     pub expr: AstPtr<ast::Expr>,
+    // `Some` or `Ok` depending on whether the return type is Result or Option
+    pub required: String,
 }
 
-impl Diagnostic for MissingOkInTailExpr {
+impl Diagnostic for MissingOkOrSomeInTailExpr {
     fn code(&self) -> DiagnosticCode {
-        DiagnosticCode("missing-ok-in-tail-expr")
+        DiagnosticCode("missing-ok-or-some-in-tail-expr")
     }
     fn message(&self) -> String {
-        "wrap return expression in Ok".to_string()
+        format!("wrap return expression in {}", self.required)
     }
     fn display_source(&self) -> InFile<SyntaxNodePtr> {
         InFile { file_id: self.file, value: self.expr.clone().into() }
diff --git a/crates/hir_ty/src/diagnostics/expr.rs b/crates/hir_ty/src/diagnostics/expr.rs
index b4e453411..a1c484fdf 100644
--- a/crates/hir_ty/src/diagnostics/expr.rs
+++ b/crates/hir_ty/src/diagnostics/expr.rs
@@ -11,8 +11,8 @@ use crate::{
     db::HirDatabase,
     diagnostics::{
         match_check::{is_useful, MatchCheckCtx, Matrix, PatStack, Usefulness},
-        MismatchedArgCount, MissingFields, MissingMatchArms, MissingOkInTailExpr, MissingPatFields,
-        RemoveThisSemicolon,
+        MismatchedArgCount, MissingFields, MissingMatchArms, MissingOkOrSomeInTailExpr,
+        MissingPatFields, RemoveThisSemicolon,
     },
     utils::variant_data,
     ApplicationTy, InferenceResult, Ty, TypeCtor,
@@ -306,27 +306,40 @@ impl<'a, 'b> ExprValidator<'a, 'b> {
         };
 
         let core_result_path = path![core::result::Result];
+        let core_option_path = path![core::option::Option];
 
         let resolver = self.owner.resolver(db.upcast());
         let core_result_enum = match resolver.resolve_known_enum(db.upcast(), &core_result_path) {
             Some(it) => it,
             _ => return,
         };
+        let core_option_enum = match resolver.resolve_known_enum(db.upcast(), &core_option_path) {
+            Some(it) => it,
+            _ => return,
+        };
 
         let core_result_ctor = TypeCtor::Adt(AdtId::EnumId(core_result_enum));
-        let params = match &mismatch.expected {
+        let core_option_ctor = TypeCtor::Adt(AdtId::EnumId(core_option_enum));
+
+        let (params, required) = match &mismatch.expected {
             Ty::Apply(ApplicationTy { ctor, parameters }) if ctor == &core_result_ctor => {
-                parameters
+                (parameters, "Ok".to_string())
+            }
+            Ty::Apply(ApplicationTy { ctor, parameters }) if ctor == &core_option_ctor => {
+                (parameters, "Some".to_string())
             }
             _ => return,
         };
 
-        if params.len() == 2 && params[0] == mismatch.actual {
+        if params.len() > 0 && params[0] == mismatch.actual {
             let (_, source_map) = db.body_with_source_map(self.owner.into());
 
             if let Ok(source_ptr) = source_map.expr_syntax(id) {
-                self.sink
-                    .push(MissingOkInTailExpr { file: source_ptr.file_id, expr: source_ptr.value });
+                self.sink.push(MissingOkOrSomeInTailExpr {
+                    file: source_ptr.file_id,
+                    expr: source_ptr.value,
+                    required,
+                });
             }
         }
     }
diff --git a/crates/hir_ty/src/tests/macros.rs b/crates/hir_ty/src/tests/macros.rs
index 1953da7be..c64f0b5b5 100644
--- a/crates/hir_ty/src/tests/macros.rs
+++ b/crates/hir_ty/src/tests/macros.rs
@@ -371,6 +371,37 @@ expand!();
 }
 
 #[test]
+fn infer_macro_with_dollar_crate_in_def_site() {
+    check_types(
+        r#"
+//- /main.rs crate:main deps:foo
+use foo::expand;
+
+macro_rules! list {
+    ($($tt:tt)*) => { $($tt)* }
+}
+
+fn test() {
+    let r = expand!();
+    r;
+  //^ u128
+}
+
+//- /lib.rs crate:foo
+#[macro_export]
+macro_rules! expand {
+    () => { list!($crate::m!()) };
+}
+
+#[macro_export]
+macro_rules! m {
+    () => { 0u128 };
+}
+"#,
+    );
+}
+
+#[test]
 fn infer_type_value_non_legacy_macro_use_as() {
     check_infer(
         r#"
diff --git a/crates/ide/src/diagnostics.rs b/crates/ide/src/diagnostics.rs
index 6931a6190..055c0a79c 100644
--- a/crates/ide/src/diagnostics.rs
+++ b/crates/ide/src/diagnostics.rs
@@ -125,7 +125,7 @@ pub(crate) fn diagnostics(
         .on::<hir::diagnostics::MissingFields, _>(|d| {
             res.borrow_mut().push(diagnostic_with_fix(d, &sema));
         })
-        .on::<hir::diagnostics::MissingOkInTailExpr, _>(|d| {
+        .on::<hir::diagnostics::MissingOkOrSomeInTailExpr, _>(|d| {
             res.borrow_mut().push(diagnostic_with_fix(d, &sema));
         })
         .on::<hir::diagnostics::NoSuchField, _>(|d| {
@@ -305,6 +305,40 @@ mod tests {
     }
 
     #[test]
+    fn test_wrap_return_type_option() {
+        check_fix(
+            r#"
+//- /main.rs crate:main deps:core
+use core::option::Option::{self, Some, None};
+
+fn div(x: i32, y: i32) -> Option<i32> {
+    if y == 0 {
+        return None;
+    }
+    x / y$0
+}
+//- /core/lib.rs crate:core
+pub mod result {
+    pub enum Result<T, E> { Ok(T), Err(E) }
+}
+pub mod option {
+    pub enum Option<T> { Some(T), None }
+}
+"#,
+            r#"
+use core::option::Option::{self, Some, None};
+
+fn div(x: i32, y: i32) -> Option<i32> {
+    if y == 0 {
+        return None;
+    }
+    Some(x / y)
+}
+"#,
+        );
+    }
+
+    #[test]
     fn test_wrap_return_type() {
         check_fix(
             r#"
@@ -321,6 +355,9 @@ fn div(x: i32, y: i32) -> Result<i32, ()> {
 pub mod result {
     pub enum Result<T, E> { Ok(T), Err(E) }
 }
+pub mod option {
+    pub enum Option<T> { Some(T), None }
+}
 "#,
             r#"
 use core::result::Result::{self, Ok, Err};
@@ -352,6 +389,9 @@ fn div<T>(x: T) -> Result<T, i32> {
 pub mod result {
     pub enum Result<T, E> { Ok(T), Err(E) }
 }
+pub mod option {
+    pub enum Option<T> { Some(T), None }
+}
 "#,
             r#"
 use core::result::Result::{self, Ok, Err};
@@ -385,6 +425,9 @@ fn div(x: i32, y: i32) -> MyResult<i32> {
 pub mod result {
     pub enum Result<T, E> { Ok(T), Err(E) }
 }
+pub mod option {
+    pub enum Option<T> { Some(T), None }
+}
 "#,
             r#"
 use core::result::Result::{self, Ok, Err};
@@ -414,12 +457,15 @@ fn foo() -> Result<(), i32> { 0 }
 pub mod result {
     pub enum Result<T, E> { Ok(T), Err(E) }
 }
+pub mod option {
+    pub enum Option<T> { Some(T), None }
+}
 "#,
         );
     }
 
     #[test]
-    fn test_wrap_return_type_not_applicable_when_return_type_is_not_result() {
+    fn test_wrap_return_type_not_applicable_when_return_type_is_not_result_or_option() {
         check_no_diagnostics(
             r#"
 //- /main.rs crate:main deps:core
@@ -433,6 +479,9 @@ fn foo() -> SomeOtherEnum { 0 }
 pub mod result {
     pub enum Result<T, E> { Ok(T), Err(E) }
 }
+pub mod option {
+    pub enum Option<T> { Some(T), None }
+}
 "#,
         );
     }
diff --git a/crates/ide/src/diagnostics/fixes.rs b/crates/ide/src/diagnostics/fixes.rs
index 71ec4df92..d7ad88ed5 100644
--- a/crates/ide/src/diagnostics/fixes.rs
+++ b/crates/ide/src/diagnostics/fixes.rs
@@ -3,7 +3,7 @@
 use hir::{
     db::AstDatabase,
     diagnostics::{
-        Diagnostic, IncorrectCase, MissingFields, MissingOkInTailExpr, NoSuchField,
+        Diagnostic, IncorrectCase, MissingFields, MissingOkOrSomeInTailExpr, NoSuchField,
         RemoveThisSemicolon, UnresolvedModule,
     },
     HasSource, HirDisplay, InFile, Semantics, VariantDef,
@@ -94,15 +94,17 @@ impl DiagnosticWithFix for MissingFields {
     }
 }
 
-impl DiagnosticWithFix for MissingOkInTailExpr {
+impl DiagnosticWithFix for MissingOkOrSomeInTailExpr {
     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 replacement = format!("{}({})", self.required, tail_expr.syntax());
+        let edit = TextEdit::replace(tail_expr_range, replacement);
         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))
+        let name = if self.required == "Ok" { "Wrap with Ok" } else { "Wrap with Some" };
+        Some(Fix::new(name, source_change, tail_expr_range))
     }
 }
 
diff --git a/crates/ide_db/src/apply_change.rs b/crates/ide_db/src/apply_change.rs
index 71c19ed13..c770a236b 100644
--- a/crates/ide_db/src/apply_change.rs
+++ b/crates/ide_db/src/apply_change.rs
@@ -145,6 +145,7 @@ impl RootDatabase {
             hir::db::MacroDefQuery
             hir::db::ParseMacroExpansionQuery
             hir::db::MacroExpandQuery
+            hir::db::HygieneFrameQuery
 
             // DefDatabase
             hir::db::ItemTreeQuery
diff --git a/crates/mbe/src/mbe_expander/matcher.rs b/crates/mbe/src/mbe_expander/matcher.rs
index fdc8844ce..c6d615c81 100644
--- a/crates/mbe/src/mbe_expander/matcher.rs
+++ b/crates/mbe/src/mbe_expander/matcher.rs
@@ -150,7 +150,7 @@ fn match_subtree(
                     res.add_err(err!("leftover tokens"));
                 }
             }
-            Op::Var { name, kind } => {
+            Op::Var { name, kind, .. } => {
                 let kind = match kind {
                     Some(k) => k,
                     None => {
diff --git a/crates/mbe/src/mbe_expander/transcriber.rs b/crates/mbe/src/mbe_expander/transcriber.rs
index 720531237..27b2ac777 100644
--- a/crates/mbe/src/mbe_expander/transcriber.rs
+++ b/crates/mbe/src/mbe_expander/transcriber.rs
@@ -100,8 +100,8 @@ fn expand_subtree(
                 err = err.or(e);
                 arena.push(tt.into());
             }
-            Op::Var { name, .. } => {
-                let ExpandResult { value: fragment, err: e } = expand_var(ctx, &name);
+            Op::Var { name, id, .. } => {
+                let ExpandResult { value: fragment, err: e } = expand_var(ctx, &name, *id);
                 err = err.or(e);
                 push_fragment(arena, fragment);
             }
@@ -118,14 +118,11 @@ fn expand_subtree(
     ExpandResult { value: tt::Subtree { delimiter: template.delimiter, token_trees: tts }, err }
 }
 
-fn expand_var(ctx: &mut ExpandCtx, v: &SmolStr) -> ExpandResult<Fragment> {
-    if v == "crate" {
-        // We simply produce identifier `$crate` here. And it will be resolved when lowering ast to Path.
-        let tt =
-            tt::Leaf::from(tt::Ident { text: "$crate".into(), id: tt::TokenId::unspecified() })
-                .into();
-        ExpandResult::ok(Fragment::Tokens(tt))
-    } else if !ctx.bindings.contains(v) {
+fn expand_var(ctx: &mut ExpandCtx, v: &SmolStr, id: tt::TokenId) -> ExpandResult<Fragment> {
+    // We already handle $crate case in mbe parser
+    debug_assert!(v != "crate");
+
+    if !ctx.bindings.contains(v) {
         // Note that it is possible to have a `$var` inside a macro which is not bound.
         // For example:
         // ```
@@ -142,14 +139,8 @@ fn expand_var(ctx: &mut ExpandCtx, v: &SmolStr) -> ExpandResult<Fragment> {
         let tt = tt::Subtree {
             delimiter: None,
             token_trees: vec![
-                tt::Leaf::from(tt::Punct {
-                    char: '$',
-                    spacing: tt::Spacing::Alone,
-                    id: tt::TokenId::unspecified(),
-                })
-                .into(),
-                tt::Leaf::from(tt::Ident { text: v.clone(), id: tt::TokenId::unspecified() })
-                    .into(),
+                tt::Leaf::from(tt::Punct { char: '$', spacing: tt::Spacing::Alone, id }).into(),
+                tt::Leaf::from(tt::Ident { text: v.clone(), id }).into(),
             ],
         }
         .into();
diff --git a/crates/mbe/src/parser.rs b/crates/mbe/src/parser.rs
index 2f3ebc831..f3047972d 100644
--- a/crates/mbe/src/parser.rs
+++ b/crates/mbe/src/parser.rs
@@ -8,7 +8,7 @@ use crate::{tt_iter::TtIter, ExpandError, MetaTemplate};
 
 #[derive(Clone, Debug, PartialEq, Eq)]
 pub(crate) enum Op {
-    Var { name: SmolStr, kind: Option<SmolStr> },
+    Var { name: SmolStr, kind: Option<SmolStr>, id: tt::TokenId },
     Repeat { subtree: MetaTemplate, kind: RepeatKind, separator: Option<Separator> },
     Leaf(tt::Leaf),
     Subtree(MetaTemplate),
@@ -106,18 +106,25 @@ fn next_op<'a>(first: &tt::TokenTree, src: &mut TtIter<'a>, mode: Mode) -> Resul
                         }
                         let name = UNDERSCORE.clone();
                         let kind = eat_fragment_kind(src, mode)?;
-                        Op::Var { name, kind }
+                        let id = punct.id;
+                        Op::Var { name, kind, id }
+                    }
+                    tt::Leaf::Ident(ident) if ident.text == "crate" => {
+                        // We simply produce identifier `$crate` here. And it will be resolved when lowering ast to Path.
+                        Op::Leaf(tt::Leaf::from(tt::Ident { text: "$crate".into(), id: ident.id }))
                     }
                     tt::Leaf::Ident(ident) => {
                         let name = ident.text.clone();
                         let kind = eat_fragment_kind(src, mode)?;
-                        Op::Var { name, kind }
+                        let id = ident.id;
+                        Op::Var { name, kind, id }
                     }
                     tt::Leaf::Literal(lit) => {
                         if is_boolean_literal(&lit) {
                             let name = lit.text.clone();
                             let kind = eat_fragment_kind(src, mode)?;
-                            Op::Var { name, kind }
+                            let id = lit.id;
+                            Op::Var { name, kind, id }
                         } else {
                             bail!("bad var 2");
                         }
diff --git a/crates/mbe/src/tests.rs b/crates/mbe/src/tests.rs
index 1d9afb4fb..d854985c5 100644
--- a/crates/mbe/src/tests.rs
+++ b/crates/mbe/src/tests.rs
@@ -1080,6 +1080,19 @@ fn test_vertical_bar_with_pat() {
 }
 
 #[test]
+fn test_dollar_crate_lhs_is_not_meta() {
+    parse_macro(
+        r#"
+macro_rules! foo {
+    ($crate) => {};
+    () => {0};
+}
+    "#,
+    )
+    .assert_expand_items(r#"foo!{}"#, r#"0"#);
+}
+
+#[test]
 fn test_lifetime() {
     parse_macro(
         r#"