Fixes GoTo Implementation for intrinsics

Closes Request textDocument/implementation failed. #80

CHANGELOG.md

@@ -1,5 +1,12 @@
 # CHANGELONG
 
+## 2.2.10
+
+### Fixed
+
+- Fixes GoTo Implementation error for intrinsics
+  ([#80](https://github.com/gnikit/fortls/issues/80))
+
 ## 2.2.9
 
 ### Changed

fortls/langserver.py

@@ -1122,6 +1122,9 @@ def serve_implementation(self, request: dict):
         var_obj = self.get_definition(file_obj, def_line, def_char)
         if var_obj is None:
             return None
+        # Intrinsics do not have implementations we can access
+        if isinstance(var_obj, fortran_intrinsic_obj):
+            return None
         # Construct implementation reference
         if var_obj.parent.get_type() == CLASS_TYPE_ID:
             impl_obj = var_obj.link_obj

test/test_server_implementation.py

@@ -35,3 +35,13 @@ def test_implementation_type_bound():
     errcode, results = run_request(string, ["-n", "1"])
     assert errcode == 0
     assert results[1] == create(test_dir / "subdir" / "test_free.f90", 49, 11, 28)
+
+
+def test_implementation_intrinsics():
+    """Go to implementation of implicit methods is handled gracefully"""
+    string = write_rpc_request(1, "initialize", {"rootPath": str(test_dir / "rename")})
+    file_path = test_dir / "rename" / "test_rename_intrinsic.f90"
+    string += imp_request(file_path, 11, 18)
+    errcode, results = run_request(string, ["-n", "1"])
+    assert errcode == 0
+    assert results[1] is None