From 86f8f3e949616616b542382f741b823eff9a5949 Mon Sep 17 00:00:00 2001
From: Jules Villard <jul@fb.com>
Date: Tue, 18 Sep 2018 09:03:16 -0700
Subject: [PATCH] [log] log dying message and backtrace to log file

Summary:
Previously we wouldn't flush the formatter hence the error message would
generally not make it to the log file. Add the backtrace too, although only the
first few lines appear for some reason...

Reviewed By: ngorogiannis

Differential Revision: D9915499

fbshipit-source-id: 43cd9e36e
---
 infer/src/base/Die.ml     | 15 +++++++++++----
 infer/src/base/Die.mli    |  2 +-
 infer/src/base/Logging.ml |  7 ++++++-
 3 files changed, 18 insertions(+), 6 deletions(-)

diff --git a/infer/src/base/Die.ml b/infer/src/base/Die.ml
index a7d99eaf4..2acae3d10 100644
--- a/infer/src/base/Die.ml
+++ b/infer/src/base/Die.ml
@@ -17,14 +17,21 @@ exception InferUserError of string
 
 exception InferExit of int
 
-let raise_error error ~msg =
+let raise_error ?backtrace error ~msg =
+  let do_raise exn =
+    match backtrace with
+    | None ->
+        raise exn
+    | Some backtrace ->
+        Caml.Printexc.raise_with_backtrace exn backtrace
+  in
   match error with
   | ExternalError ->
-      raise (InferExternalError msg)
+      do_raise (InferExternalError msg)
   | InternalError ->
-      raise (InferInternalError msg)
+      do_raise (InferInternalError msg)
   | UserError ->
-      raise (InferUserError msg)
+      do_raise (InferUserError msg)
 
 
 let log_uncaught_exception_callback_ref = ref (fun _ ~exitcode:_ -> ())
diff --git a/infer/src/base/Die.mli b/infer/src/base/Die.mli
index 806577772..fee443233 100644
--- a/infer/src/base/Die.mli
+++ b/infer/src/base/Die.mli
@@ -32,7 +32,7 @@ val log_uncaught_exception : exn -> exitcode:int -> unit
 val die : error -> ('a, Format.formatter, unit, _) format4 -> 'a
 (** Raise the corresponding exception. *)
 
-val raise_error : error -> msg:string -> 'a
+val raise_error : ?backtrace:Caml.Printexc.raw_backtrace -> error -> msg:string -> 'a
 
 type style = Error | Fatal | Normal | Warning
 
diff --git a/infer/src/base/Logging.ml b/infer/src/base/Logging.ml
index 82b3753e5..e6dba8359 100644
--- a/infer/src/base/Logging.ml
+++ b/infer/src/base/Logging.ml
@@ -304,7 +304,12 @@ let log_of_kind error fmt =
 
 
 let die error msg =
-  F.kasprintf (fun msg -> log_of_kind error "%s@\n" msg ; raise_error error ~msg) msg
+  let backtrace = Caml.Printexc.get_raw_backtrace () in
+  F.kasprintf
+    (fun msg ->
+      log_of_kind error "%s@\n%s@." msg (Caml.Printexc.raw_backtrace_to_string backtrace) ;
+      raise_error ~backtrace error ~msg )
+    msg
 
 
 (* create new channel from the log file, and dumps the contents of the temporary log buffer there *)