load json config files lazily and at most once

Summary:
The checkers check was causing perf issues because it kept loading the json of
inferconfig. To prevent this from happening again, load json files inside
config.ml, and only export `Yojson.Basic.json Lazy.t` values to other modules.

Also move the list of checks disabled by default into config.ml for better
discoverability.

Reviewed By: jberdine

Differential Revision: D3293041

fbshipit-source-id: 4a38b26

infer/lib/python/inferlib/jwlib.py

@@ -277,6 +277,12 @@ class AnalyzerWithFrontendWrapper(analyze.AnalyzerWrapper):
         if not self.args.absolute_paths:
             infer_cmd += ['-project_root', self.args.project_root]
 
+        if os.path.isfile(self.javac.suppress_warnings_out) and \
+           os.path.getsize(self.javac.suppress_warnings_out) == 0:
+            with codecs.open(self.javac.suppress_warnings_out, 'w',
+                             encoding=config.CODESET) as json_file:
+                json_file.write('{}')
+
         infer_cmd += [
             '-results_dir', self.args.infer_out,
             '-verbose_out', self.javac.verbose_out,

infer/src/backend/CommandLineOption.ml

@@ -262,14 +262,14 @@ let mk_symbol_opt ~symbols ?(deprecated=[]) ~long ?short ?exes ?(meta="") doc =
     ~mk_spec:(fun set -> Arg.Symbol (strings, set))
 
 let mk_symbol_seq ?(default=[]) ~symbols ?(deprecated=[]) ~long ?short ?exes ?(meta="") doc =
-  let strings = IList.map fst symbols in
   let sym_to_str = IList.map (fun (x,y) -> (y,x)) symbols in
   let of_string str = IList.assoc string_equal str symbols in
   let to_string sym = IList.assoc ( = ) sym sym_to_str in
   mk ~deprecated ~long ?short ~default ?exes ~meta:(" ,-separated sequence" ^ meta) doc
     ~default_to_string:(fun syms -> String.concat " " (IList.map to_string syms))
-    ~mk_setter:(fun var str_seq -> var := IList.map of_string (Str.split (Str.regexp ",") str_seq))
-    ~mk_spec:(fun set -> Arg.Symbol (strings, set))
+    ~mk_setter:(fun var str_seq ->
+        var := IList.map of_string (Str.split (Str.regexp_string ",") str_seq))
+    ~mk_spec:(fun set -> Arg.String set)
 
 let anon_fun = ref (fun arg -> raise (Arg.Bad ("unexpected anonymous argument: " ^ arg)))
 

infer/src/backend/config.ml

@@ -58,6 +58,10 @@ let bound_error_allowed_in_procedure_call = true
 
 let captured_dir_name = "captured"
 
+let checks_disabled_by_default = [
+  "GLOBAL_VARIABLE_INITIALIZED_WITH_FUNCTION_OR_METHOD_CALL";
+]
+
 let default_failure_name = "ASSERTION_FAILURE"
 
 let default_in_zip_results_dir = "infer"
@@ -134,6 +138,8 @@ let specs_files_suffix = ".specs"
 
 let start_filename = ".start"
 
+let suppress_warnings_annotations_long = "suppress-warnings-annotations"
+
 (** If true performs taint analysis *)
 let taint_analysis = true
 
@@ -627,7 +633,7 @@ and subtype_multirange =
     "Use the multirange subtyping domain"
 
 and suppress_warnings_out =
-  CLOpt.mk_string_opt ~deprecated:["suppress_warnings_out"] ~long:"suppress-warnings-annotations"
+  CLOpt.mk_string_opt ~deprecated:["suppress_warnings_out"] ~long:suppress_warnings_annotations_long
     ~exes:CLOpt.[J] ~meta:"path" "Path to list of collected @SuppressWarnings annotations"
 
 (** command line flag: if true, produce a svg file *)
@@ -962,7 +968,6 @@ and dotty_cfg_libs = !dotty_cfg_libs
 and eradicate = !eradicate
 and err_file_cmdline = !err_file
 and infer_cache = !infer_cache
-and inferconfig_home = !inferconfig_home
 and iterations = !iterations
 and javac_verbose_out = !verbose_out
 and join_cond = !join_cond
@@ -1006,7 +1011,6 @@ and spec_abs_level = !spec_abs_level
 and specs_library = !specs_library
 and stats_mode = !stats
 and subtype_multirange = !subtype_multirange
-and suppress_warnings_annotations = !suppress_warnings_out
 and svg = !svg
 and symops_per_iteration = !symops_per_iteration
 and test = !test
@@ -1023,3 +1027,32 @@ and write_dotty = !write_dotty
 and write_html = !write_html
 and xml_specs = !xml_specs
 and zip_libraries = !zip_libraries
+
+let inferconfig_json =
+  let inferconfig_path =
+    match !inferconfig_home, project_root with
+    | Some dir, _ | _, Some dir -> Filename.concat dir inferconfig_file
+    | None, None -> inferconfig_file in
+  lazy (
+    match read_optional_json_file inferconfig_path with
+    | Ok json -> json
+    | Error msg ->
+        F.fprintf F.err_formatter "Could not read or parse Infer config in %s:@\n%s@."
+          inferconfig_path msg;
+        exit 1)
+
+and suppress_warnings_json = lazy (
+  let error msg =
+    F.fprintf F.err_formatter "There was an issue reading the option %s.@\n"
+      suppress_warnings_annotations_long ;
+    F.fprintf F.err_formatter "If you did not call %s directly, this is likely a bug in Infer.@\n"
+      (Filename.basename Sys.executable_name) ;
+    F.fprintf F.err_formatter "%s@." msg ;
+    exit 1 in
+  match !suppress_warnings_out with
+  | Some path -> (
+      match read_optional_json_file path with
+      | Ok json -> json
+      | Error msg -> error ("Could not read or parse the supplied " ^ path ^ ":\n" ^ msg))
+  | None ->
+      error ("Error: The option " ^ suppress_warnings_annotations_long ^ " was not provided"))

infer/src/backend/config.mli

@@ -38,6 +38,7 @@ val assign : string
 val attributes_dir_name : string
 val backend_stats_dir_name : string
 val bound_error_allowed_in_procedure_call : bool
+val checks_disabled_by_default : string list
 val captured_dir_name : string
 val default_failure_name : string
 val default_in_zip_results_dir : string
@@ -123,7 +124,7 @@ val dotty_cfg_libs : bool
 val eradicate : bool
 val err_file_cmdline : string
 val infer_cache : string option
-val inferconfig_home : string option
+val inferconfig_json : Yojson.Basic.json Lazy.t
 val iterations : int
 val javac_verbose_out : string
 val join_cond : int
@@ -168,7 +169,7 @@ val spec_abs_level : int
 val specs_library : string list
 val stats_mode : bool
 val subtype_multirange : bool
-val suppress_warnings_annotations : string option
+val suppress_warnings_json : Yojson.Basic.json Lazy.t
 val svg : bool
 val symops_per_iteration : int
 val test : bool

infer/src/backend/inferconfig.ml

@@ -13,9 +13,11 @@ module L = Logging
 
 (** Look up a key in a json file containing a list of strings *)
 let lookup_string_list key json =
+  try
     Yojson.Basic.Util.filter_member key [json]
     |> Yojson.Basic.Util.flatten
     |> Yojson.Basic.Util.filter_string
+  with Yojson.Basic.Util.Type_error _ -> []
 
 type path_filter = DB.source_file -> bool
 type error_filter = Localise.t -> bool
@@ -145,11 +147,11 @@ let rec translate json_key accu (json : Yojson.Basic.json) : pattern list =
   | _ -> assert false
 
 (* Creates a list of matching patterns for the given inferconfig file *)
-let load_patterns json_key inferconfig =
+let load_patterns json_key json =
   let found =
     Yojson.Basic.Util.filter_member
       json_key
-      [Yojson.Basic.from_file inferconfig] in
+      [json] in
   IList.fold_left (translate json_key) [] found
 
 
@@ -200,7 +202,7 @@ end
 
 module type Matcher = sig
   type matcher = DB.source_file -> Procname.t -> bool
-  val load_matcher : string -> matcher
+  val load_matcher : Yojson.Basic.json Lazy.t -> matcher
 end
 
 (* Module to create matcher based on source file names or class names and method names *)
@@ -212,7 +214,6 @@ struct
   let default_matcher : matcher =
     fun _ _ -> false
 
-
   let create_method_matcher m_patterns =
     if m_patterns = [] then
       default_matcher
@@ -260,12 +261,8 @@ struct
     fun source_file proc_name ->
       m_matcher source_file proc_name || s_matcher source_file proc_name
 
-  let load_matcher inferconfig =
-    if Sys.file_exists inferconfig then
-      create_file_matcher (load_patterns M.json_key inferconfig)
-    else
-      default_matcher
-
+  let load_matcher json =
+    create_file_matcher (load_patterns M.json_key (Lazy.force json))
 
   let _pp_pattern fmt pattern =
     let pp_string fmt s =
@@ -301,19 +298,15 @@ struct
 
   type matcher = (string -> bool) -> Procname.t -> bool
 
-  let default_matcher _ _ = false
-
-  let load_matcher inferconfig =
-    if Sys.file_exists inferconfig then
+  let load_matcher json =
+    let patterns = load_patterns M.json_key (Lazy.force json) in
     fun is_subtype proc_name ->
       let is_matching = function
         | Method_pattern (language, mp) ->
             is_subtype mp.class_name
             && Option.map_default (match_method language proc_name) false mp.method_name
         | _ -> failwith "Expecting method pattern" in
-        IList.exists is_matching (load_patterns M.json_key inferconfig)
-    else
-      default_matcher
+      IList.exists is_matching patterns
 
 end
 
@@ -333,20 +326,8 @@ module ModeledExpensiveMatcher = OverridesMatcher(struct
     let json_key = "modeled_expensive"
   end)
 
-let disabled_checks_by_default = [
-  "GLOBAL_VARIABLE_INITIALIZED_WITH_FUNCTION_OR_METHOD_CALL"
-]
-
-let inferconfig () =
-  match Config.inferconfig_home, Config.project_root with
-  | Some dir, _ | _, Some dir -> Filename.concat dir Config.inferconfig_file
-  | None, None -> Config.inferconfig_file
-
 let load_filters analyzer =
-  let inferconfig_file = inferconfig () in
-  if Sys.file_exists inferconfig_file then
-    try
-      let json = Yojson.Basic.from_file inferconfig_file in
+  let lazy json = Config.inferconfig_json in
   let inferconfig =
     {
       whitelist = lookup_string_list (analyzer ^ "_whitelist") json;
@@ -356,9 +337,6 @@ let load_filters analyzer =
       suppress_errors = lookup_string_list (analyzer ^ "_suppress_errors") json;
     } in
   Some inferconfig
-    with Sys_error _ -> None
-  else None
-
 
 let filters_from_inferconfig inferconfig : filters =
   let path_filter =
@@ -394,20 +372,17 @@ let create_filters analyzer =
 
 (* Decide whether a checker or error type is enabled or disabled based on*)
 (* white/black listing in .inferconfig and the default value *)
-let is_checker_enabled checker_name =
+let is_checker_enabled =
   let black_listed_checks = lazy (
-    try
-      lookup_string_list "disable_checks"
-        (Yojson.Basic.from_file (inferconfig ()))
-    with _ -> []) in
+    lookup_string_list "disable_checks" (Lazy.force Config.inferconfig_json)) in
   let white_listed_checks = lazy (
-    try
-      lookup_string_list "enable_checks"
-        (Yojson.Basic.from_file (inferconfig ()))
-    with _ -> []) in
-  match IList.mem (=) checker_name (Lazy.force black_listed_checks), IList.mem (=) checker_name (Lazy.force white_listed_checks) with
+    lookup_string_list "enable_checks" (Lazy.force Config.inferconfig_json)) in
+  (* return a closure so that we automatically memoize the json lookups thanks to lazy *)
+  function checker_name ->
+  match IList.mem (=) checker_name (Lazy.force black_listed_checks),
+        IList.mem (=) checker_name (Lazy.force white_listed_checks) with
   | false, false -> (* if it's not amond white/black listed then we use default value *)
-      not (IList.mem (=) checker_name disabled_checks_by_default)
+      not (IList.mem (=) checker_name Config.checks_disabled_by_default)
   | true, false -> (* if it's blacklisted and not whitelisted then it should be disabled *)
       false
   | false, true -> (* if it is not blacklisted and it is whitelisted then it should be enabled *)
@@ -440,10 +415,4 @@ let test () =
     (Sys.getcwd ())
 
 let skip_translation_headers =
-  lazy (
-    match
-      lookup_string_list "skip_translation_headers"
-        (Yojson.Basic.from_file (inferconfig ()))
-    with
-    | exception _ -> []
-    | headers -> headers)
+  lazy (lookup_string_list "skip_translation_headers" (Lazy.force Config.inferconfig_json))

infer/src/backend/inferconfig.mli

@@ -9,9 +9,6 @@
 
 open! Utils
 
-(** get the path to the .inferconfig file *)
-val inferconfig : unit -> string
-
 (** Filter type for a source file *)
 type path_filter = DB.source_file -> bool
 
@@ -36,7 +33,7 @@ val create_filters : analyzer -> filters
 
 module type Matcher = sig
   type matcher = DB.source_file -> Procname.t -> bool
-  val load_matcher : string -> matcher
+  val load_matcher : Yojson.Basic.json Lazy.t -> matcher
 end
 
 module NeverReturnNull : Matcher
@@ -47,7 +44,7 @@ module SuppressWarningsMatcher : Matcher
 
 module ModeledExpensiveMatcher : sig
   type matcher = (string -> bool) -> Procname.t -> bool
-  val load_matcher : string -> matcher
+  val load_matcher : Yojson.Basic.json Lazy.t -> matcher
 end
 
 (** Load the config file and list the files to report on *)
@@ -55,5 +52,6 @@ val test: unit -> unit
 
 val skip_translation_headers : string list Lazy.t
 
-(* is_checker_enabled error_name is true if error_name is whitelisted in .inferconfig or if it's enabled by default *)
+(** is_checker_enabled [error_name] is [true] if [error_name] is whitelisted in .inferconfig or if
+    it's enabled by default *)
 val is_checker_enabled : string -> bool

infer/src/backend/utils.ml

@@ -16,6 +16,10 @@ module F = Format
     functions and builtin equality. Use IList instead. *)
 module List = struct end
 
+type ('a, 'b) result =
+  | Ok of 'a
+  | Error of 'b
+
 (** initial process times *)
 let initial_times = Unix.times ()
 
@@ -563,3 +567,11 @@ let string_append_crc_cutoff ?(cutoff=100) ?(key="") name =
     let name_for_crc = name ^ key in
     string_crc_hex32 name_for_crc in
   name_up_to_cutoff ^ "." ^ crc_str
+
+let read_optional_json_file path =
+  if Sys.file_exists path then
+    try
+      Ok (Yojson.Basic.from_file path)
+    with Sys_error msg | Yojson.Json_error msg ->
+      Error msg
+  else Ok (`Assoc [])

infer/src/backend/utils.mli

@@ -16,6 +16,10 @@
     functions and builtin equality. Use IList instead. *)
 module List : sig end
 
+type ('a, 'b) result =
+  | Ok of 'a
+  | Error of 'b
+
 (** initial process times *)
 val initial_times : Unix.process_times
 
@@ -249,3 +253,5 @@ val analyzers: analyzer list
 val string_of_analyzer: analyzer -> string
 
 val analyzer_of_string: string -> analyzer
+
+val read_optional_json_file : string -> (Yojson.Basic.json, string) result

infer/src/checkers/annotationReachability.ml

@@ -106,8 +106,7 @@ let expensive_overrides_unexpensive =
 
 let is_modeled_expensive =
   let matcher =
-    lazy (let config_file = Inferconfig.inferconfig () in
-          Inferconfig.ModeledExpensiveMatcher.load_matcher config_file) in
+    lazy (Inferconfig.ModeledExpensiveMatcher.load_matcher Config.inferconfig_json) in
   fun tenv proc_name -> match proc_name with
     | Procname.Java proc_name_java ->
         not (Builtin.is_registered proc_name) &&

infer/src/java/jAnnotation.ml

@@ -14,17 +14,9 @@ open Javalib_pack
 
 
 let is_suppress_warnings_annotated =
-  let matcher =
-    lazy
-      (let default_matcher = fun _ -> false in
-       match Config.suppress_warnings_annotations with
-       | Some f ->
-           (try
-              let m = Inferconfig.SuppressWarningsMatcher.load_matcher f in
-              (m DB.source_file_empty)
-            with Yojson.Json_error _ ->
-              default_matcher)
-       | None -> failwith "Local config expected!") in
+  let matcher = lazy (
+    Inferconfig.SuppressWarningsMatcher.load_matcher Config.suppress_warnings_json
+      DB.source_file_empty) in
   fun proc_name ->
     (Lazy.force matcher) proc_name
 

infer/src/java/jMain.ml

@@ -136,9 +136,8 @@ let do_all_files classpath sources classes =
   let tenv = load_tenv () in
   let linereader = Printer.LineReader.create () in
   let skip_translation_matcher =
-    Inferconfig.SkipTranslationMatcher.load_matcher (Inferconfig.inferconfig ()) in
-  let never_null_matcher =
-    Inferconfig.NeverReturnNull.load_matcher (Inferconfig.inferconfig ()) in
+    Inferconfig.SkipTranslationMatcher.load_matcher Config.inferconfig_json in
+  let never_null_matcher = Inferconfig.NeverReturnNull.load_matcher Config.inferconfig_json in
   let skip source_file =
     skip_translation_matcher source_file Procname.empty_block in
   let translate_source_file basename (package_opt, _) source_file =