From 9ef594545d6ac68920c1875c8186cbfd5d6b3029 Mon Sep 17 00:00:00 2001
From: Sasha Manzyuk <manzyuk@fb.com>
Date: Tue, 2 Jul 2019 07:19:07 -0700
Subject: [PATCH] Improve the error message of "primary error position not in
 current file" errors

Summary: Make it clear in the error message that this is a bug in the type checker that should be reported to the Hack team and provide instructions for doing that.

Reviewed By: andrewjkennedy

Differential Revision: D16074272

fbshipit-source-id: bc8e4737a0608573ad344d0324bfc1d6521e77b3
---
 hphp/hack/src/errors/dune              |  5 ++++-
 hphp/hack/src/errors/errors.ml         |  7 ++++---
 hphp/hack/src/stubs/badpos_sentinel.ml | 12 ++++++++++++
 3 files changed, 20 insertions(+), 4 deletions(-)
 create mode 100644 hphp/hack/src/stubs/badpos_sentinel.ml

diff --git a/hphp/hack/src/errors/dune b/hphp/hack/src/errors/dune
index a15e84d6ec0..423bf88bcf4 100644
--- a/hphp/hack/src/errors/dune
+++ b/hphp/hack/src/errors/dune
@@ -8,4 +8,7 @@
     server_load_flag
     (select coroutine_errors.ml from
     (facebook -> facebook/coroutine_errors.ml)
-    (-> ../stubs/coroutine_errors.ml))))
+    (-> ../stubs/coroutine_errors.ml))
+    (select badpos_sentinel.ml from
+    (facebook -> facebook/badpos_sentinel.ml)
+    (-> ../stubs/badpos_sentinel.ml))))
diff --git a/hphp/hack/src/errors/errors.ml b/hphp/hack/src/errors/errors.ml
index 0dbe3d4a059..b9a4e961dc6 100644
--- a/hphp/hack/src/errors/errors.ml
+++ b/hphp/hack/src/errors/errors.ml
@@ -110,7 +110,6 @@ let (error_map : error files_t ref) = ref Relative_path.Map.empty
 let accumulate_errors = ref false
 (* Some filename when declaring *)
 let in_lazy_decl = ref None
-let badpos_sentinel = "PRIMARY ERROR POSITION IS NOT IN CURRENT FILE: please fix"
 
 let try_with_result f1 f2 =
   let error_map_copy = !error_map in
@@ -132,7 +131,9 @@ let try_with_result f1 f2 =
   | Some (code,l) ->
    (* Remove bad position sentinel if present: we might be about to add a new primary
     * error position*)
-   let l = match l with (_, msg) :: l when msg = badpos_sentinel -> l | _ -> l in
+   let l = match l with
+     | (_, msg) :: l when msg = Badpos_sentinel.message -> l
+     | _ -> l in
    f2 result (code,l)
 
 let do_ f =
@@ -587,7 +588,7 @@ let check_pos_msg pos_msg_l =
   let pos = fst (List.hd_exn pos_msg_l) in
   let current_file = fst !current_context in
   if current_file <> Relative_path.default && Pos.filename pos <> current_file
-  then (pos, badpos_sentinel) :: pos_msg_l
+  then (Pos.make_from current_file, Badpos_sentinel.message) :: pos_msg_l
   else pos_msg_l
 
 let rec add_applied_fixme code pos =
diff --git a/hphp/hack/src/stubs/badpos_sentinel.ml b/hphp/hack/src/stubs/badpos_sentinel.ml
new file mode 100644
index 00000000000..129adf863a7
--- /dev/null
+++ b/hphp/hack/src/stubs/badpos_sentinel.ml
@@ -0,0 +1,12 @@
+(**
+ * Copyright (c) 2018, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the "hack" directory of this source tree.
+ *
+ *)
+
+let message =
+  "Type checking of this file produced an error with the primary position " ^
+  "in a different file. Please file a bug."
-- 
2.11.4.GIT