Fix some issues with merging the capture from several buck targets.

Reviewed By: jberdine

Differential Revision: D3125949

fb-gh-sync-id: dd9e263
fbshipit-source-id: dd9e263

infer/src/backend/inferanalyze.ml

@@ -240,8 +240,7 @@ let () = (* parse command-line arguments *)
     begin
       L.err "ERROR: results directory %s does not exist@.@." !Config.results_dir;
       print_usage_exit ()
-    end ;
+    end
-  if !Config.merge then MergeCapture.merge_captured_targets ()
 
 let analyze_exe_env exe_env =
   let init_time = Unix.gettimeofday () in
@@ -374,6 +373,7 @@ let () =
       process_cluster_cmdline fname;
       finish_logging ()
   | None ->
+      if !Config.merge then MergeCapture.merge_captured_targets ();
       let clusters = DB.find_source_dirs () in
       L.err "Found %d source files in %s@."
         (IList.length clusters) !Config.results_dir;

infer/src/backend/mergeCapture.ml

@@ -16,7 +16,12 @@ module F = Format
     is used to determine whether a captured directory needs to be merged. *)
 let check_timestamp_of_symlinks = true
 
-let buck_out () = Filename.concat (Filename.dirname !Config.results_dir) "buck-out"
+let buck_out () =
+  match !Config.project_root with
+  | Some root ->
+      Filename.concat root "buck-out"
+  | None ->
+      Filename.concat (Filename.dirname !Config.results_dir) "buck-out"
 
 let infer_deps () = Filename.concat !Config.results_dir "infer-deps.txt"
 
@@ -43,6 +48,12 @@ let empty_stats () =
     targets_merged = 0;
   }
 
+let link_exists s =
+  try
+    let _ = Unix.lstat s in
+    true
+  with Unix.Unix_error _ -> false
+
 (** Create symbolic links recursively from the destination to the source.
     Replicate the structure of the source directory in the destination,
     with files replaced by links to the source. *)
@@ -61,14 +72,14 @@ let rec slink ~stats src dst =
     end
   else
     begin
-      if Sys.file_exists dst then Sys.remove dst;
+      if link_exists dst then Unix.unlink dst;
       Unix.symlink src dst;
-      (* Set the accessed and modified time of the new symlink to be slightly in the future.  Due to
+      (* Set the accessed and modified time of the original file slightly in the past.  Due to
          the coarse precision of the timestamps, it is possible for the source and destination of a
          link to have the same modification time. When this happens, the files will be considered to
          need re-analysis every time, indefinitely. *)
-      let near_future = Unix.gettimeofday () +. 1. in
+      let near_past = Unix.gettimeofday () -. 1. in
-      Unix.utimes dst near_future near_future ;
+      Unix.utimes src near_past near_past;
       stats.files_linked <- stats.files_linked + 1;
     end