[litho] utility function for iterating over all call chains encoded in the domain

Summary:
and add mli. We already had the logic for iterating over call chains, but it was overfitted to the should-update analysis.
Will use the generalized version in a follow-up.

Reviewed By: jvillard

Differential Revision: D6740692

fbshipit-source-id: 8c0d89f

infer/src/checkers/Litho.ml

@@ -90,7 +90,7 @@ module TransferFunctions (CFG : ProcCfg.S) = struct
           let return_access_path = Domain.LocalAccessPath.make (return_base, []) caller_pname in
           let return_calls =
             (try Domain.find return_access_path astate with Not_found -> Domain.CallSet.empty)
-            |> Domain.CallSet.add {receiver; procname= callee_procname}
+            |> Domain.CallSet.add (Domain.MethodCall.make receiver callee_procname)
           in
           Domain.add return_access_path return_calls astate
         else
@@ -126,27 +126,6 @@ let report access_path call_chain summary =
   Reporting.log_error summary ~loc ~ltr exn
 
 
-let unroll_call call astate summary =
-  let max_depth = Domain.cardinal astate in
-  let rec unroll_call_ ({receiver; procname}: Domain.MethodCall.t) (acc, depth) =
-    let acc' = procname :: acc in
-    let depth' = depth + 1 in
-    let is_cycle access_path =
-      (* detect direct cycles and cycles due to mutual recursion *)
-      Domain.LocalAccessPath.equal access_path receiver || depth' > max_depth
-    in
-    try
-      let calls' = Domain.find receiver astate in
-      Domain.CallSet.iter
-        (fun call ->
-          if not (is_cycle call.receiver) then unroll_call_ call (acc', depth')
-          else report receiver.access_path acc' summary )
-        calls'
-    with Not_found -> report receiver.access_path acc' summary
-  in
-  unroll_call_ call ([], 0)
-
-
 let should_report proc_desc =
   match Procdesc.get_proc_name proc_desc with
   | Typ.Procname.Java java_pname -> (
@@ -155,10 +134,14 @@ let should_report proc_desc =
       false
 
 
-let report_call_chains post summary =
-  Domain.iter
-    (fun _ call_set -> Domain.CallSet.iter (fun call -> unroll_call call post summary) call_set)
-    post
+let report_graphql_getters summary access_path call_chain =
+  let call_strings = List.map ~f:(Typ.Procname.to_simplified_string ~withclass:false) call_chain in
+  let call_string = String.concat ~sep:"." call_strings in
+  let message = F.asprintf "%a.%s" AccessPath.pp access_path call_string in
+  let exn = Exceptions.Checkers (IssueType.graphql_field_access, Localise.verbatim_desc message) in
+  let loc = Specs.get_loc summary in
+  let ltr = [Errlog.make_trace_element 0 loc message []] in
+  Reporting.log_error summary ~loc ~ltr exn
 
 
 let postprocess astate proc_desc : Domain.astate =
@@ -171,7 +154,9 @@ let checker {Callbacks.summary; proc_desc; tenv} =
   let proc_data = ProcData.make_default proc_desc tenv in
   match Analyzer.compute_post proc_data ~initial:Domain.empty with
   | Some post ->
-      if should_report proc_desc then report_call_chains post summary ;
+      ( if should_report proc_desc then
+          let f = report_graphql_getters summary in
+          Domain.iter_call_chains ~f post ) ;
       let payload = postprocess post proc_desc in
       Summary.update_summary payload summary
   | None ->

infer/src/checkers/LithoDomain.ml

@@ -11,7 +11,6 @@ open! IStd
 module F = Format
 module L = Logging
 
-(** Access path + its parent procedure *)
 module LocalAccessPath = struct
   type t = {access_path: AccessPath.t; parent: Typ.Procname.t} [@@deriving compare]
 
@@ -30,10 +29,11 @@ module LocalAccessPath = struct
   let pp fmt t = AccessPath.pp fmt t.access_path
 end
 
-(** Called procedure + it's receiver *)
 module MethodCall = struct
   type t = {receiver: LocalAccessPath.t; procname: Typ.Procname.t} [@@deriving compare]
 
+  let make receiver procname = {receiver; procname}
+
   let pp fmt {receiver; procname} =
     F.fprintf fmt "%a.%a" LocalAccessPath.pp receiver Typ.Procname.pp procname
 end
@@ -62,3 +62,31 @@ let substitute ~(f_sub: LocalAccessPath.t -> LocalAccessPath.t option) astate =
       in
       add access_path' call_set' acc )
     astate empty
+
+
+let iter_call_chains_with_suffix ~f call_suffix astate =
+  let max_depth = cardinal astate in
+  let rec unroll_call_ ({receiver; procname}: MethodCall.t) (acc, depth) =
+    let acc' = procname :: acc in
+    let depth' = depth + 1 in
+    let is_cycle access_path =
+      (* detect direct cycles and cycles due to mutual recursion *)
+      LocalAccessPath.equal access_path receiver || depth' > max_depth
+    in
+    try
+      let calls' = find receiver astate in
+      CallSet.iter
+        (fun call ->
+          if not (is_cycle call.receiver) then unroll_call_ call (acc', depth')
+          else f receiver.access_path acc' )
+        calls'
+    with Not_found -> f receiver.access_path acc'
+  in
+  unroll_call_ call_suffix ([], 0)
+
+
+let iter_call_chains ~f astate =
+  iter
+    (fun _ call_set ->
+      CallSet.iter (fun call -> iter_call_chains_with_suffix ~f call astate) call_set )
+    astate

infer/src/checkers/LithoDomain.mli

@@ -0,0 +1,48 @@
+(*
+ * Copyright (c) 2018 - present Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ *)
+
+open! IStd
+module F = Format
+
+(** Access path + its parent procedure *)
+module LocalAccessPath : sig
+  type t = private {access_path: AccessPath.t; parent: Typ.Procname.t} [@@deriving compare]
+
+  val make : AccessPath.t -> Typ.Procname.t -> t
+
+  val to_formal_option : t -> FormalMap.t -> t option
+
+  val pp : F.formatter -> t -> unit
+end
+
+(** Called procedure + its receiver *)
+module MethodCall : sig
+  type t = private {receiver: LocalAccessPath.t; procname: Typ.Procname.t} [@@deriving compare]
+
+  val make : LocalAccessPath.t -> Typ.Procname.t -> t
+
+  val pp : F.formatter -> t -> unit
+end
+
+module CallSet : module type of AbstractDomain.FiniteSet (MethodCall)
+
+include module type of AbstractDomain.Map (LocalAccessPath) (CallSet)
+
+val substitute : f_sub:(LocalAccessPath.t -> LocalAccessPath.t option) -> astate -> astate
+(** Substitute each access path in the domain using [f_sub]. If [f_sub] returns None, the
+    original access path is retained; otherwise, the new one is used *)
+
+val iter_call_chains_with_suffix :
+  f:(AccessPath.t -> Typ.Procname.t list -> unit) -> MethodCall.t -> astate -> unit
+(** Unroll the domain to enumerate all the call chains ending in [call] and apply [f] to each
+    maximal chain. For example, if the domain encodes the chains foo().bar().goo() and foo().baz(),
+    [f] will be called once on foo().bar().goo() and once on foo().baz() *)
+
+val iter_call_chains : f:(AccessPath.t -> Typ.Procname.t list -> unit) -> astate -> unit
+(** Apply [f] to each maximal call chain encoded in [astate] *)