diff --git a/crates/hir/src/lib.rs b/crates/hir/src/lib.rs
index 469ed5b5e6b..0d0e757fca7 100644
--- a/crates/hir/src/lib.rs
+++ b/crates/hir/src/lib.rs
@@ -844,7 +844,7 @@ pub fn method_params(self, db: &dyn HirDatabase) -> Option<Vec<Param>> {
     }
 
     pub fn is_unsafe(self, db: &dyn HirDatabase) -> bool {
-        db.function_data(self.id).is_unsafe
+        db.function_data(self.id).qualifier.is_unsafe
     }
 
     pub fn diagnostics(self, db: &dyn HirDatabase, sink: &mut DiagnosticSink) {
diff --git a/crates/hir_def/src/data.rs b/crates/hir_def/src/data.rs
index aea53d527e1..b09da06979d 100644
--- a/crates/hir_def/src/data.rs
+++ b/crates/hir_def/src/data.rs
@@ -9,7 +9,7 @@
     attr::Attrs,
     body::Expander,
     db::DefDatabase,
-    item_tree::{AssocItem, ItemTreeId, ModItem},
+    item_tree::{AssocItem, FunctionQualifier, ItemTreeId, ModItem},
     type_ref::{TypeBound, TypeRef},
     visibility::RawVisibility,
     AssocContainerId, AssocItemId, ConstId, ConstLoc, FunctionId, FunctionLoc, HasModule, ImplId,
@@ -26,9 +26,9 @@ pub struct FunctionData {
     /// can be called as a method.
     pub has_self_param: bool,
     pub has_body: bool,
-    pub is_unsafe: bool,
+    pub qualifier: FunctionQualifier,
+    pub is_in_extern_block: bool,
     pub is_varargs: bool,
-    pub is_extern: bool,
     pub visibility: RawVisibility,
 }
 
@@ -46,9 +46,9 @@ pub(crate) fn fn_data_query(db: &dyn DefDatabase, func: FunctionId) -> Arc<Funct
             attrs: item_tree.attrs(db, krate, ModItem::from(loc.id.value).into()),
             has_self_param: func.has_self_param,
             has_body: func.has_body,
-            is_unsafe: func.is_unsafe,
+            qualifier: func.qualifier.clone(),
+            is_in_extern_block: func.is_in_extern_block,
             is_varargs: func.is_varargs,
-            is_extern: func.is_extern,
             visibility: item_tree[func.visibility].clone(),
         })
     }
diff --git a/crates/hir_def/src/item_tree.rs b/crates/hir_def/src/item_tree.rs
index 09bcb10dc0c..d8f22d44296 100644
--- a/crates/hir_def/src/item_tree.rs
+++ b/crates/hir_def/src/item_tree.rs
@@ -24,7 +24,7 @@
 use profile::Count;
 use rustc_hash::FxHashMap;
 use smallvec::SmallVec;
-use syntax::{ast, match_ast, SyntaxKind};
+use syntax::{ast, match_ast, SmolStr, SyntaxKind};
 
 use crate::{
     attr::{Attrs, RawAttrs},
@@ -551,16 +551,25 @@ pub struct Function {
     pub generic_params: GenericParamsId,
     pub has_self_param: bool,
     pub has_body: bool,
-    pub is_unsafe: bool,
+    pub qualifier: FunctionQualifier,
     /// Whether the function is located in an `extern` block (*not* whether it is an
     /// `extern "abi" fn`).
-    pub is_extern: bool,
+    pub is_in_extern_block: bool,
     pub params: Box<[Idx<TypeRef>]>,
     pub is_varargs: bool,
     pub ret_type: Idx<TypeRef>,
     pub ast_id: FileAstId<ast::Fn>,
 }
 
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct FunctionQualifier {
+    pub is_default: bool,
+    pub is_const: bool,
+    pub is_async: bool,
+    pub is_unsafe: bool,
+    pub abi: Option<SmolStr>,
+}
+
 #[derive(Debug, Clone, Eq, PartialEq)]
 pub struct Struct {
     pub name: Name,
diff --git a/crates/hir_def/src/item_tree/lower.rs b/crates/hir_def/src/item_tree/lower.rs
index 240fdacf94c..6b5438dc93d 100644
--- a/crates/hir_def/src/item_tree/lower.rs
+++ b/crates/hir_def/src/item_tree/lower.rs
@@ -391,14 +391,33 @@ fn lower_function(&mut self, func: &ast::Fn) -> Option<FileItemTreeId<Function>>
         let has_body = func.body().is_some();
 
         let ast_id = self.source_ast_id_map.ast_id(func);
+        let qualifier = FunctionQualifier {
+            is_default: func.default_token().is_some(),
+            is_const: func.const_token().is_some(),
+            is_async: func.async_token().is_some(),
+            is_unsafe: func.unsafe_token().is_some(),
+            abi: func.abi().map(|abi| {
+                // FIXME: Abi::abi() -> Option<SyntaxToken>?
+                match abi.syntax().last_token() {
+                    Some(tok) if tok.kind() == SyntaxKind::STRING => {
+                        // FIXME: Better way to unescape?
+                        tok.text().trim_matches('"').into()
+                    }
+                    _ => {
+                        // `extern` default to be `extern "C"`.
+                        "C".into()
+                    }
+                }
+            }),
+        };
         let mut res = Function {
             name,
             visibility,
             generic_params: GenericParamsId::EMPTY,
             has_self_param,
             has_body,
-            is_unsafe: func.unsafe_token().is_some(),
-            is_extern: false,
+            qualifier,
+            is_in_extern_block: false,
             params,
             is_varargs,
             ret_type,
@@ -608,8 +627,8 @@ fn lower_extern_block(&mut self, block: &ast::ExternBlock) -> Vec<ModItem> {
                         ast::ExternItem::Fn(ast) => {
                             let func_id = self.lower_function(&ast)?;
                             let func = &mut self.data().functions[func_id.index];
-                            func.is_unsafe = is_intrinsic_fn_unsafe(&func.name);
-                            func.is_extern = true;
+                            func.qualifier.is_unsafe = is_intrinsic_fn_unsafe(&func.name);
+                            func.is_in_extern_block = true;
                             func_id.into()
                         }
                         ast::ExternItem::Static(ast) => {
diff --git a/crates/hir_ty/src/diagnostics/decl_check.rs b/crates/hir_ty/src/diagnostics/decl_check.rs
index 3605ca5816c..982ad5b9e00 100644
--- a/crates/hir_ty/src/diagnostics/decl_check.rs
+++ b/crates/hir_ty/src/diagnostics/decl_check.rs
@@ -91,7 +91,7 @@ fn allowed(&self, id: AttrDefId, allow_name: &str) -> bool {
 
     fn validate_func(&mut self, func: FunctionId) {
         let data = self.db.function_data(func);
-        if data.is_extern {
+        if data.is_in_extern_block {
             cov_mark::hit!(extern_func_incorrect_case_ignored);
             return;
         }
diff --git a/crates/hir_ty/src/diagnostics/unsafe_check.rs b/crates/hir_ty/src/diagnostics/unsafe_check.rs
index 20bb6482796..44a7e550647 100644
--- a/crates/hir_ty/src/diagnostics/unsafe_check.rs
+++ b/crates/hir_ty/src/diagnostics/unsafe_check.rs
@@ -32,7 +32,7 @@ pub(super) fn validate_body(&mut self, db: &dyn HirDatabase) {
         let def = self.owner.into();
         let unsafe_expressions = unsafe_expressions(db, self.infer.as_ref(), def);
         let is_unsafe = match self.owner {
-            DefWithBodyId::FunctionId(it) => db.function_data(it).is_unsafe,
+            DefWithBodyId::FunctionId(it) => db.function_data(it).qualifier.is_unsafe,
             DefWithBodyId::StaticId(_) | DefWithBodyId::ConstId(_) => false,
         };
         if is_unsafe
@@ -86,7 +86,7 @@ fn walk_unsafe(
     match expr {
         &Expr::Call { callee, .. } => {
             if let Some(func) = infer[callee].as_fn_def(db) {
-                if db.function_data(func).is_unsafe {
+                if db.function_data(func).qualifier.is_unsafe {
                     unsafe_exprs.push(UnsafeExpr { expr: current, inside_unsafe_block });
                 }
             }
@@ -103,7 +103,7 @@ fn walk_unsafe(
         Expr::MethodCall { .. } => {
             if infer
                 .method_resolution(current)
-                .map(|func| db.function_data(func).is_unsafe)
+                .map(|func| db.function_data(func).qualifier.is_unsafe)
                 .unwrap_or(false)
             {
                 unsafe_exprs.push(UnsafeExpr { expr: current, inside_unsafe_block });