Suppress warnings on SourceFile creation, if desired

Summary:
When dealing with differential's comparisons, SourceFiles in reports may not exist anymore because of changes between revisions.
Disable user visible warnings if desired, through the labeled argument `~warn_on_error`

Reviewed By: jvillard

Differential Revision: D5217097

fbshipit-source-id: 7a1542b

infer/src/base/SourceFile.ml

@@ -34,14 +34,14 @@ module Map = Caml.Map.Make (OrderedSourceFile)
 
 module Set = Caml.Set.Make (OrderedSourceFile)
 
-let from_abs_path fname =
+let from_abs_path ?(warn_on_error=true) fname =
   if Filename.is_relative fname then
     (failwithf
        "ERROR: Path %s is relative, when absolute path was expected .@."
        fname);
   (* try to get realpath of source file. Use original if it fails *)
-  let fname_real = try Utils.realpath fname with Unix.Unix_error _ -> fname in
-  let project_root_real = Utils.realpath Config.project_root in
+  let fname_real = try Utils.realpath ~warn_on_error fname with Unix.Unix_error _ -> fname in
+  let project_root_real = Utils.realpath ~warn_on_error Config.project_root in
   let models_dir_real = Config.models_src_dir in
   match Utils.filename_to_relative ~root:project_root_real fname_real with
   | Some path -> RelativeProjectRoot path
@@ -113,7 +113,7 @@ let path_exists abs_path =
     String.Table.set exists_cache ~key:abs_path ~data:result;
     result
 
-let of_header header_file =
+let of_header ?(warn_on_error=true) header_file =
   let abs_path = to_abs_path header_file in
   let source_exts = ["c"; "cc"; "cpp"; "cxx"; "m"; "mm"] in
   let header_exts = ["h"; "hh"; "hpp"; "hxx"] in
@@ -124,14 +124,14 @@ let of_header header_file =
         List.find ~f:path_exists possible_files
       )
     | _ -> None in
-  Option.map ~f:from_abs_path file_opt
+  Option.map ~f:(from_abs_path ~warn_on_error) file_opt
 
-let create path =
+let create ?(warn_on_error=true) path =
   if Filename.is_relative path then
     (* sources in changed-files-index may be specified relative to project root *)
     RelativeProjectRoot path
   else
-    from_abs_path path
+    from_abs_path ~warn_on_error path
 
 let changed_files_set =
   Option.bind Config.changed_files_index Utils.read_file |>

infer/src/base/SourceFile.mli

@@ -38,12 +38,15 @@ val invalid : string -> t
 (** equality of source files *)
 val equal : t -> t -> bool
 
-(** create source file from absolute path *)
-val from_abs_path : string -> t
+(** create source file from absolute path.
+    WARNING: If warn_on_error is false, no warning will be shown whenever an error occurs for
+    the given path (e.g. if it does not exist). *)
+val from_abs_path : ?warn_on_error:bool -> string -> t
 
-(* Create a SourceFile from a given path. If relative, it assumes it is w.r.t.
-   project root *)
-val create : string -> t
+(* Create a SourceFile from a given path. If relative, it assumes it is w.r.t. project root.
+   WARNING: If warn_on_error is false, no warning will be shown whenever an error occurs for
+   the given path (e.g. if it does not exist). *)
+val create : ?warn_on_error:bool -> string -> t
 
 (** Returns true if the file is a C++ model *)
 val is_cpp_model : t -> bool
@@ -57,8 +60,10 @@ val is_under_project_root : t -> bool
 val line_count : t -> int
 
 (** Return approximate source file corresponding to the parameter if it's header file and
-    file exists. returns None otherwise *)
-val of_header : t -> t option
+    file exists. returns None otherwise.
+    WARNING: If warn_on_error is false, no warning will be shown whenever an error occurs for
+    the given SourceFile (e.g. if it does not exist).*)
+val of_header : ?warn_on_error:bool -> t -> t option
 
 (** pretty print t *)
 val pp : Format.formatter -> t -> unit

infer/src/base/Utils.ml

@@ -255,7 +255,7 @@ let create_dir dir =
 
 let realpath_cache = Hashtbl.create 1023
 
-let realpath path =
+let realpath ?(warn_on_error=true) path =
   match Hashtbl.find realpath_cache path with
   | exception Not_found -> (
       match Filename.realpath path with
@@ -263,8 +263,9 @@ let realpath path =
           Hashtbl.add realpath_cache path (Ok realpath);
           realpath
       | exception Unix.Unix_error (code, f, arg) ->
-          F.eprintf
-            "WARNING: Failed to resolve file %s with \"%s\" @\n@." arg (Unix.error_message code);
+          if warn_on_error then
+            F.eprintf
+              "WARNING: Failed to resolve file %s with \"%s\" @\n@." arg (Unix.error_message code);
           (* cache failures as well *)
           Hashtbl.add realpath_cache path (Error (code, f, arg));
           raise (Unix.Unix_error (code, f, arg))

infer/src/base/Utils.mli

@@ -71,9 +71,11 @@ val shell_escape_command : string list -> string
 (** create a directory if it does not exist already *)
 val create_dir : string -> unit
 
-(** [realpath path] returns path with all symbolic links resolved. It caches results of previous
-    calls to avoid expensive system calls *)
-val realpath : string -> string
+(** [realpath warn_on_error path] returns path with all symbolic links resolved.
+    It caches results of previous calls to avoid expensive system calls.
+    WARNING: If warn_on_error is false, no warning will be shown whenever an error occurs for
+    the given path (e.g. if it does not exist). *)
+val realpath : ?warn_on_error:bool -> string -> string
 
 (** wraps a function expecting 2 arguments in another that temporarily redirects stderr to /dev/null
     for the duration of the function call *)