[report] Print Cost/ConfigImpact json reports only for changed files

Summary: This diff prints cost and config impact checkers' json reports only for the changed files.

Reviewed By: ezgicicek

Differential Revision: D28707192

fbshipit-source-id: d949771f2

infer/src/base/SourceFile.ml

@@ -276,17 +276,21 @@ let changed_sources_from_changed_files changed_files =
       with _exn -> changed_files_set )
 
 
-let read_config_changed_files () =
-  match Config.changed_files_index with
-  | None ->
-      None
-  | Some index -> (
-    match Utils.read_file index with
-    | Ok lines ->
-        Some (changed_sources_from_changed_files lines)
-    | Error error ->
-        L.external_error "Error reading the changed files index '%s': %s@." index error ;
-        None )
+let read_config_changed_files =
+  let result =
+    lazy
+      ( match Config.changed_files_index with
+      | None ->
+          None
+      | Some index -> (
+        match Utils.read_file index with
+        | Ok lines ->
+            Some (changed_sources_from_changed_files lines)
+        | Error error ->
+            L.external_error "Error reading the changed files index '%s': %s@." index error ;
+            None ) )
+  in
+  fun () -> Lazy.force result
 
 
 module SQLite = struct

infer/src/integration/JsonReports.ml

@@ -325,6 +325,15 @@ end
 
 module JsonConfigImpactPrinter = MakeJsonListPrinter (JsonConfigImpactPrinterElt)
 
+let is_in_changed_files {Location.file} =
+  match SourceFile.read_config_changed_files () with
+  | None ->
+      (* when Config.changed_files_index is not given *)
+      true
+  | Some changed_files ->
+      SourceFile.Set.mem file changed_files
+
+
 let mk_error_filter filters proc_name file error_name =
   (Config.write_html || not (IssueType.(equal skip_function) error_name))
   && filters.Inferconfig.path_filter file
@@ -339,7 +348,7 @@ let collect_issues proc_name proc_location err_log issues_acc =
 
 
 let write_costs proc_name loc cost_opt (outfile : Utils.outfile) =
-  if not (Cost.is_report_suppressed proc_name) then
+  if (not (Cost.is_report_suppressed proc_name)) && is_in_changed_files loc then
     JsonCostsPrinter.pp outfile.fmt {loc; proc_name; cost_opt}
 
 
@@ -357,7 +366,7 @@ let get_all_config_fields () =
 
 let write_config_impact all_config_fields proc_name loc config_impact_opt (outfile : Utils.outfile)
     =
-  if ExternalConfigImpactData.is_in_config_data_file proc_name then
+  if ExternalConfigImpactData.is_in_config_data_file proc_name && is_in_changed_files loc then
     let config_impact_opt =
       Option.map config_impact_opt
         ~f:

infer/tests/build_systems/incremental_analysis_cost_change/costs_summary.json.exp

@@ -1 +1 @@
-{"top":{"current":0,"previous":0},"unreachable":{"current":0,"previous":0},"zero":{"current":0,"previous":0},"degrees":[{"degree":0,"current":10,"previous":10},{"degree":100,"current":4,"previous":1},{"degree":200,"current":0,"previous":1}]}
+{"top":{"current":0,"previous":0},"unreachable":{"current":0,"previous":0},"zero":{"current":0,"previous":0},"degrees":[{"degree":0,"current":10,"previous":7},{"degree":100,"current":4,"previous":0},{"degree":200,"current":0,"previous":1}]}