[nullsafe] Path to third-party signatures can be accepted in absolute or relative forms.

Summary:
Ability to accept relative path is convenient for testing and local
debugging.

Ability to accept absolute paths is needed for buck integration - buck
knows absolute path (to properly invalidate cache when the content of
the folder is changed) and passes it to infer.

Reviewed By: artempyanykh

Differential Revision: D18370407

fbshipit-source-id: be7f12ae1

infer/man/man1/infer-full.txt

@@ -1540,8 +1540,8 @@ INTERNAL OPTIONS
 
        --nullsafe-third-party-signatures string
            Path to a folder with annotated signatures of third-party methods
-           to be taken into account by nullsafe. Path is relative to
-           .inferconfig folder.
+           to be taken into account by nullsafe. Path is either relative to
+           .inferconfig folder or absolute
 
        --nullsafe-third-party-signatures-reset
            Cancel the effect of --nullsafe-third-party-signatures.

infer/src/base/Config.ml

@@ -1761,7 +1761,7 @@ and nullable_annotation =
 and nullsafe_third_party_signatures =
   CLOpt.mk_string_opt ~long:"nullsafe-third-party-signatures"
     "Path to a folder with annotated signatures of third-party methods to be taken into account \
-     by nullsafe. Path is relative to .inferconfig folder."
+     by nullsafe. Path is either relative to .inferconfig folder or absolute"
 
 
 and nullsafe_strict_containers =

infer/src/nullsafe/NullsafeInit.ml

@@ -21,20 +21,26 @@ let load_third_party_repo ~absolute_path_to_repo_dir =
         absolute_path_to_repo_dir
 
 
-let get_absolute_path_to_repo_dir relative_path_to_repo_dir =
-  match Config.inferconfig_dir with
-  | None ->
-      Logging.die Logging.InternalError
-        "Could not locate .inferconfig directory, which is required for resolving the path to \
-         third party annotation repository"
-  | Some inferconfig_dir ->
-      inferconfig_dir ^/ relative_path_to_repo_dir
+let get_absolute_path_to_repo_dir path_to_repo_dir =
+  if Filename.is_absolute path_to_repo_dir then
+    (* By agreement, this means absolute path *)
+    path_to_repo_dir
+  else
+    (* By agreement, this means path relative to inferconfig dir *)
+    match Config.inferconfig_dir with
+    | None ->
+        Logging.die Logging.InternalError
+          "Could not locate .inferconfig directory, which is required for resolving the path to \
+           third party annotation repository"
+    | Some inferconfig_dir ->
+        inferconfig_dir ^/ path_to_repo_dir
 
 
 let create_global_storage () =
   match Config.nullsafe_third_party_signatures with
-  | Some dir ->
-      load_third_party_repo ~absolute_path_to_repo_dir:(get_absolute_path_to_repo_dir dir)
+  | Some path_to_repo_dir ->
+      load_third_party_repo
+        ~absolute_path_to_repo_dir:(get_absolute_path_to_repo_dir path_to_repo_dir)
   (* Create empty *)
   | None ->
       ThirdPartyAnnotationInfo.create_storage ()