Add the --log-events flag to turn on events logging

Reviewed By: mbouaziz

Differential Revision: D6611878

fbshipit-source-id: 6137f77

infer/src/base/Config.ml

@@ -1426,6 +1426,12 @@ and join_cond =
 |}
 
 
+and log_events =
+  CLOpt.mk_bool ~long:"log-events"
+    ~in_help:CLOpt.([(Run, manual_generic)])
+    "Turn on the feature that logs events in a machine-readable format"
+
+
 and log_file =
   CLOpt.mk_string ~deprecated:["out_file"; "-out-file"] ~long:"log-file" ~meta:"file"
     ~default:"logs" "Specify the file to use for logging"
@@ -2521,6 +2527,8 @@ and load_average =
 
 and load_analysis_results = !load_results
 
+and log_events = !log_events
+
 and log_file = !log_file
 
 and makefile_cmdline = !makefile

infer/src/base/Config.mli

@@ -523,6 +523,8 @@ val liveness : bool
 
 val load_analysis_results : string option
 
+val log_events : bool
+
 val log_file : string
 
 val makefile_cmdline : string

infer/src/base/EventLogger.ml

@@ -30,10 +30,11 @@ module IO = struct
 
 
   let prepare () =
-    close () ;
-    let fname = events_dir ^/ (Unix.getpid () |> Pid.to_string) ^ log_file_extension in
-    let oc = Pervasives.open_out_gen [Open_append; Open_creat] 0o666 fname in
-    out_chan := Some oc
+    if Config.log_events then (
+      close () ;
+      let fname = events_dir ^/ (Unix.getpid () |> Pid.to_string) ^ log_file_extension in
+      let oc = Pervasives.open_out_gen [Open_append; Open_creat] 0o666 fname in
+      out_chan := Some oc )
 
 
   let write fmt =