Fix enum crash issue

Author: CppCXY

CHANGELOG.md

@@ -5,6 +5,9 @@
 ---
 ## [0.8.2] - Unreleased
 
+### 🐛 Fixed
+- **Enum Variable Parameter Issue**: Fixed a crash issue when checking enum variable as parameter
+
 ## [0.8.1] - 2025-6-14
 
 ### 🔧 Changed

crates/emmylua_code_analysis/src/diagnostic/checker/check_field.rs

@@ -438,16 +438,10 @@ fn check_enum_is_param(
     prefix_typ: &LuaType,
     index_expr: &LuaIndexExpr,
 ) -> Option<()> {
-    if enum_variable_is_param(
+    enum_variable_is_param(
         semantic_model.get_db(),
         &mut semantic_model.get_config().borrow_mut(),
         index_expr,
         prefix_typ,
     )
-    .is_some()
-    {
-        return Some(());
-    }
-
-    None
 }

crates/emmylua_code_analysis/src/semantic/decl/mod.rs

@@ -1,3 +1,5 @@
+use std::collections::HashSet;
+
 use emmylua_parser::{LuaAstNode, LuaIndexExpr};
 use rowan::NodeOrToken;
 
@@ -12,43 +14,6 @@ pub fn enum_variable_is_param(
     index_expr: &LuaIndexExpr,
     prefix_typ: &LuaType,
 ) -> Option<()> {
-    fn find_enum_origin(
-        db: &DbIndex,
-        cache: &mut LuaInferCache,
-        decl_id: LuaDeclId,
-    ) -> Option<LuaDeclId> {
-        let syntax_tree = db.get_vfs().get_syntax_tree(&decl_id.file_id)?;
-        let root = syntax_tree.get_red_root();
-
-        let node = db
-            .get_decl_index()
-            .get_decl(&decl_id)?
-            .get_value_syntax_id()?
-            .to_node_from_root(&root)?;
-
-        let semantic_decl = match node.into() {
-            NodeOrToken::Node(node) => {
-                infer_node_semantic_decl(db, cache, node, SemanticDeclLevel::NoTrace)
-            }
-            NodeOrToken::Token(token) => {
-                infer_token_semantic_decl(db, cache, token, SemanticDeclLevel::NoTrace)
-            }
-        };
-
-        match semantic_decl {
-            Some(LuaSemanticDeclId::Member(_)) => None,
-            Some(LuaSemanticDeclId::LuaDecl(new_decl_id)) => {
-                let decl = db.get_decl_index().get_decl(&new_decl_id)?;
-                if decl.get_value_syntax_id().is_some() {
-                    Some(find_enum_origin(db, cache, new_decl_id).unwrap_or(new_decl_id))
-                } else {
-                    Some(new_decl_id)
-                }
-            }
-            _ => None,
-        }
-    }
-
     let LuaType::Ref(id) = prefix_typ else {
         return None;
     };
@@ -70,7 +35,8 @@ pub fn enum_variable_is_param(
         return None;
     };
 
-    let origin_decl_id = find_enum_origin(db, cache, decl_id).unwrap_or(decl_id);
+    let mut decl_guard = DeclGuard::new();
+    let origin_decl_id = find_enum_origin(db, cache, decl_id, &mut decl_guard).unwrap_or(decl_id);
     let decl = db.get_decl_index().get_decl(&origin_decl_id)?;
 
     if decl.is_param() {
@@ -79,3 +45,64 @@ pub fn enum_variable_is_param(
         None
     }
 }
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct DeclGuard {
+    decl_set: HashSet<LuaDeclId>,
+}
+
+impl DeclGuard {
+    pub fn new() -> Self {
+        Self {
+            decl_set: HashSet::new(),
+        }
+    }
+
+    pub fn check(&mut self, decl_id: LuaDeclId) -> Option<()> {
+        if self.decl_set.contains(&decl_id) {
+            None
+        } else {
+            self.decl_set.insert(decl_id);
+            Some(())
+        }
+    }
+}
+
+fn find_enum_origin(
+    db: &DbIndex,
+    cache: &mut LuaInferCache,
+    decl_id: LuaDeclId,
+    decl_guard: &mut DeclGuard,
+) -> Option<LuaDeclId> {
+    decl_guard.check(decl_id)?;
+    let syntax_tree = db.get_vfs().get_syntax_tree(&decl_id.file_id)?;
+    let root = syntax_tree.get_red_root();
+
+    let node = db
+        .get_decl_index()
+        .get_decl(&decl_id)?
+        .get_value_syntax_id()?
+        .to_node_from_root(&root)?;
+
+    let semantic_decl = match node.into() {
+        NodeOrToken::Node(node) => {
+            infer_node_semantic_decl(db, cache, node, SemanticDeclLevel::NoTrace)
+        }
+        NodeOrToken::Token(token) => {
+            infer_token_semantic_decl(db, cache, token, SemanticDeclLevel::NoTrace)
+        }
+    };
+
+    match semantic_decl {
+        Some(LuaSemanticDeclId::Member(_)) => None,
+        Some(LuaSemanticDeclId::LuaDecl(new_decl_id)) => {
+            let decl = db.get_decl_index().get_decl(&new_decl_id)?;
+            if decl.get_value_syntax_id().is_some() {
+                Some(find_enum_origin(db, cache, new_decl_id, decl_guard).unwrap_or(new_decl_id))
+            } else {
+                Some(new_decl_id)
+            }
+        }
+        _ => None,
+    }
+}