[clang] less verbose logging of translation errors

Summary:
This was spammy, especially for errors which we already know about and are
caught by the frontend (then the error message would be displayed about a
translation error without context about what the error was).

Reviewed By: dulmarod

Differential Revision: D8640145

fbshipit-source-id: 8b8b8a7

infer/src/clang/cTrans.ml

@@ -3144,7 +3144,10 @@ module CTrans_funct (F : CModule_type.CFrontend) : CModule_type.CTranslation = s
 
   (** Translates a clang instruction into SIL instructions. It takes a a [trans_state] containing
       current info on the translation and it returns a [trans_result].*)
-  and instruction trans_state instr : trans_result =
+  and instruction =
+    (* log errors only at the innermost recursive call *)
+    let logged_error = ref false in
+    fun trans_state instr ->
       let pp_pointer f instr =
         let {Clang_ast_t.si_pointer}, _ = Clang_ast_proj.get_stmt_tuple instr in
         Format.pp_print_int f si_pointer
@@ -3156,22 +3159,45 @@ module CTrans_funct (F : CModule_type.CFrontend) : CModule_type.CTranslation = s
       let trans_result =
         try instruction_aux trans_state instr with e ->
           IExn.reraise_after e ~f:(fun () ->
+              let should_log_error = not !logged_error in
+              if should_log_error then (
+                (* prevent from displaying the same issue multiple times as we climb up the call
+                   stack *)
+                logged_error := true ;
                 let {Clang_ast_t.si_source_range}, _ = Clang_ast_proj.get_stmt_tuple instr in
                 let source_file =
-              trans_state.context.CContext.translation_unit_context.CFrontend_config.source_file
+                  trans_state.context.CContext.translation_unit_context
+                    .CFrontend_config.source_file
                 in
                 let loc_start =
-              CLocation.location_of_source_range ~pick_location:`Start source_file si_source_range
+                  CLocation.location_of_source_range ~pick_location:`Start source_file
+                    si_source_range
                 in
                 let loc_end =
-              CLocation.location_of_source_range ~pick_location:`End source_file si_source_range
+                  CLocation.location_of_source_range ~pick_location:`End source_file
+                    si_source_range
+                in
+                (* Unfortunately this triggers regularly so do not show the message on the console
+                   unless asked to do so or if the error will crash the frontend. *)
+                let should_display_error =
+                  Config.debug_level_capture >= 1
+                  ||
+                  match e with
+                  | CFrontend_config.Unimplemented _ | CFrontend_config.IncorrectAssumption _ ->
+                      (* these are caught by default, do not print messages unless asked to do so *)
+                      false
+                  | _ ->
+                      (* we are going to crash, print message for more context *)
+                      true
                 in
-            L.internal_error "%a: ERROR translating statement '%a'@\n" Location.pp_range
-              (loc_start, loc_end)
+                (if should_display_error then L.internal_error else L.debug Capture Quiet)
+                  "%a: ERROR translating statement '%a'@\n" Location.pp_range (loc_start, loc_end)
                   (Pp.to_string ~f:Clang_ast_proj.get_stmt_kind_string)
-              instr )
+                  instr ) )
       in
       L.(debug Capture Verbose) "@]" ;
+      (* don't forget to reset this so we output messages for future errors too *)
+      logged_error := false ;
       trans_result