have infer automatically figure out when `--merge` is needed

Reviewed By: jvillard

Differential Revision: D9942867

fbshipit-source-id: 0652925c1

infer/src/atd/runstate.atd

@@ -20,4 +20,5 @@ type run_info = {
 type t = {
   run_sequence: run_info list; (** successive runs that re-used the same results directory *)
   results_dir_format: string; (** to check if the versions of the results dir are compatible *)
+  should_merge_capture: bool; (** add --merge to 'infer analyze' if last command was a capture that needs --merge *)
 }

infer/src/base/RunState.ml

@@ -14,7 +14,8 @@ let state0 =
   { run_sequence= []
   ; results_dir_format=
       Printf.sprintf "db_filename: %s\ndb_schema: %s" ResultsDatabase.database_filename
-        ResultsDatabase.schema_hum }
+        ResultsDatabase.schema_hum
+  ; should_merge_capture= false }
 
 
 let state : Runstate_t.t ref = ref state0
@@ -66,3 +67,7 @@ let load_and_validate () =
 
 
 let reset () = state := state0
+
+let set_merge_capture onoff = Runstate_t.(state := {!state with should_merge_capture= onoff})
+
+let get_merge_capture () = !state.Runstate_t.should_merge_capture

infer/src/base/RunState.mli

@@ -10,6 +10,12 @@ open! IStd
 val add_run_to_sequence : unit -> unit
 (** add an entry with the current run date *)
 
+val set_merge_capture : bool -> unit
+(** update the 'merge after capture' smart option *)
+
+val get_merge_capture : unit -> bool
+(** fetch the value of the 'merge after capture' smart option *)
+
 val store : unit -> unit
 (** save the current state to disk *)
 

infer/src/integration/Driver.ml

@@ -279,6 +279,7 @@ let capture ~changed_files = function
               updated_buck_cmd )
             else build_cmd ) )
       in
+      if in_buck_mode && Config.flavors then ( RunState.set_merge_capture true ; RunState.store () ) ;
       run_command ~prog:infer_py ~args
         ~cleanup:(function
           | Error (`Exit_non_zero exit_code)
@@ -394,10 +395,15 @@ let analyze_and_report ?suppress_console_report ~changed_files mode =
     | PythonCapture (BBuck, _) when Config.flavors && InferCommand.equal Run Config.command ->
         (* if doing capture + analysis of buck with flavors, we always need to merge targets before the analysis phase *)
         true
+    | Analyze ->
+        RunState.get_merge_capture ()
     | _ ->
         (* else rely on the command line value *) Config.merge
   in
-  if should_merge then MergeCapture.merge_captured_targets () ;
+  if should_merge then (
+    MergeCapture.merge_captured_targets () ;
+    RunState.set_merge_capture false ;
+    RunState.store () ) ;
   if should_analyze then
     if SourceFiles.is_empty () && Config.capture then error_nothing_to_analyze mode
     else execute_analyze ~changed_files ;