[quandary] remove concept of a footprint source

Summary:
We now represent the footprint with an access trie, so this code is no longer required.
This lets us simplify things a bit

Reviewed By: jberdine

Differential Revision: D5664484

fbshipit-source-id: c35edf2

infer/src/checkers/Source.ml

@@ -29,12 +29,6 @@ module type S = sig
 
   type spec = {source: t; index: int option}
 
-  val is_footprint : t -> bool
-
-  val make_footprint : AccessPath.Abs.t -> Procdesc.t -> t
-
-  val get_footprint_access_path : t -> AccessPath.Abs.t option
-
   val get : CallSite.t -> HilExp.t list -> Tenv.t -> spec option
 
   val get_tainted_formals : Procdesc.t -> Tenv.t -> (Mangled.t * Typ.t * t option) list
@@ -43,35 +37,15 @@ end
 module Make (Kind : Kind) = struct
   module Kind = Kind
 
-  type kind =
-    | Normal of Kind.t  (** known source returned directly or transitively from a callee *)
-    | Footprint of AccessPath.Abs.t  (** unknown source read from the environment *)
-    [@@deriving compare]
-
-  let pp_kind fmt = function
-    | Normal kind
-     -> Kind.pp fmt kind
-    | Footprint ap
-     -> F.fprintf fmt "Footprint(%a)" AccessPath.Abs.pp ap
-
-  type t = {kind: kind; site: CallSite.t} [@@deriving compare]
+  type t = {kind: Kind.t; site: CallSite.t} [@@deriving compare]
 
   type spec = {source: t; index: int option}
 
-  let is_footprint t = match t.kind with Footprint _ -> true | _ -> false
-
-  let get_footprint_access_path t = match t.kind with Footprint ap -> Some ap | _ -> None
-
   let call_site t = t.site
 
-  let kind t = match t.kind with Normal kind -> kind | Footprint _ -> Kind.unknown
-
-  let make ?indexes:_ kind site = {site; kind= Normal kind}
+  let kind t = t.kind
 
-  let make_footprint ap pdesc =
-    let kind = Footprint ap in
-    let site = CallSite.make (Procdesc.get_proc_name pdesc) (Procdesc.get_loc pdesc) in
-    {site; kind}
+  let make ?indexes:_ kind site = {site; kind}
 
   let get site actuals tenv =
     match Kind.get (CallSite.pname site) actuals tenv with
@@ -88,11 +62,9 @@ module Make (Kind : Kind) = struct
         (name, typ, Option.map kind_opt ~f:(fun kind -> make kind site)))
       (Kind.get_tainted_formals pdesc tenv)
 
-  let pp fmt s = F.fprintf fmt "%a(%a)" pp_kind s.kind CallSite.pp s.site
+  let pp fmt s = F.fprintf fmt "%a(%a)" Kind.pp s.kind CallSite.pp s.site
 
-  let with_callsite t callee_site =
-    if is_footprint t then failwithf "Can't change the call site of footprint source %a" pp t ;
-    {t with site= callee_site}
+  let with_callsite t callee_site = {t with site= callee_site}
 
   module Set = PrettyPrintable.MakePPSet (struct
     type nonrec t = t
@@ -116,12 +88,6 @@ module Dummy = struct
 
   let pp _ () = ()
 
-  let is_footprint _ = false
-
-  let make_footprint _ _ = assert false
-
-  let get_footprint_access_path _ = None
-
   let get _ _ _ = None
 
   let get_tainted_formals pdesc _ =

infer/src/checkers/Source.mli

@@ -33,15 +33,6 @@ module type S = sig
     { source: t  (** type of the returned source *)
     ; index: int option  (** index of the returned source if Some; return value if None *) }
 
-  val is_footprint : t -> bool
-  (** return true if the current source is a footprint source *)
-
-  val make_footprint : AccessPath.Abs.t -> Procdesc.t -> t
-  (** create a footprint source for the value read from the given access path. *)
-
-  val get_footprint_access_path : t -> AccessPath.Abs.t option
-  (** return Some(access path) if the current source is a footprint source, None otherwise *)
-
   val get : CallSite.t -> HilExp.t list -> Tenv.t -> spec option
   (** return Some (taint spec) if the call site with the given actuals is a taint source, None otherwise *)
 

infer/src/checkers/Trace.ml

@@ -44,6 +44,8 @@ module type S = sig
 
     val of_source : Source.t -> t
 
+    val of_footprint : AccessPath.Abs.t -> t
+
     val add : Source.t -> t -> t
 
     val get_footprint_indexes : t -> IntSet.t
@@ -88,8 +90,11 @@ module type S = sig
   val of_source : Source.t -> t
   (** create a trace from a source *)
 
+  val of_footprint : AccessPath.Abs.t -> t
+  (** create a trace from a footprint access path *)
+
   val add_source : Source.t -> t -> t
-  (** ad a source to the current trace *)
+  (** add a source to the current trace *)
 
   val add_sink : Sink.t -> t -> t
   (** add a sink to the current trace. *)
@@ -183,25 +188,16 @@ module Make (Spec : Spec) = struct
 
     let is_empty {known; footprint} = Known.is_empty known && Footprint.BaseMap.is_empty footprint
 
-    let add_footprint_access_path access_path footprint =
-      Footprint.add_trace access_path true footprint
+    let of_footprint access_path =
+      let footprint = Footprint.add_trace access_path true Footprint.empty in
+      {empty with footprint}
 
     let of_source source =
-      match Source.get_footprint_access_path source with
-      | Some access_path
-       -> let footprint = add_footprint_access_path access_path Footprint.empty in
-          {empty with footprint}
-      | None
-       -> let known = Known.singleton source in
+      let known = Known.singleton source in
       {empty with known}
 
     let add source astate =
-      match Source.get_footprint_access_path source with
-      | Some access_path
-       -> let footprint = add_footprint_access_path access_path astate.footprint in
-          {astate with footprint}
-      | None
-       -> let known = Known.add source astate.known in
+      let known = Known.add source astate.known in
       {astate with known}
 
     let get_footprint_indexes {footprint} =
@@ -408,12 +404,19 @@ module Make (Spec : Spec) = struct
       ~f:(fun acc source -> trace_elems_of_source source acc)
       ~init:trace_prefix sources_with_level
 
-  let of_source source =
-    let sources = Sources.of_source source in
+  let of_sources sources =
     let passthroughs = Passthroughs.empty in
     let sinks = Sinks.empty in
     {sources; passthroughs; sinks}
 
+  let of_source source =
+    let sources = Sources.of_source source in
+    of_sources sources
+
+  let of_footprint access_path =
+    let sources = Sources.of_footprint access_path in
+    of_sources sources
+
   let add_source source t =
     let sources = Sources.add source t.sources in
     {t with sources}

infer/src/checkers/Trace.mli

@@ -46,6 +46,8 @@ module type S = sig
 
     val of_source : Source.t -> t
 
+    val of_footprint : AccessPath.Abs.t -> t
+
     val add : Source.t -> t -> t
 
     val get_footprint_indexes : t -> IntSet.t
@@ -91,8 +93,11 @@ module type S = sig
   val of_source : Source.t -> t
   (** create a trace from a source *)
 
+  val of_footprint : AccessPath.Abs.t -> t
+  (** create a trace from a footprint access path *)
+
   val add_source : Source.t -> t -> t
-  (** ad a source to the current trace *)
+  (** add a source to the current trace *)
 
   val add_sink : Sink.t -> t -> t
   (** add a sink to the current trace. *)

infer/src/quandary/ClangTrace.ml

@@ -246,18 +246,6 @@ include Trace.Make (struct
     | (Endpoint _ | EnvironmentVariable | File), Allocation
      -> (* untrusted data flowing to memory allocation *)
         true
-    | _, (Allocation | Other | ShellExec | SQL) when Source.is_footprint source
-     -> (
-        (* is this var a command line flag created by the popular gflags library? *)
-        let is_gflag pvar =
-          String.is_substring ~substring:"FLAGS_" (Pvar.get_simplified_name pvar)
-        in
-        match Option.map ~f:AccessPath.Abs.extract (Source.get_footprint_access_path source) with
-        | Some ((Var.ProgramVar pvar, _), _) when Pvar.is_global pvar && is_gflag pvar
-         -> (* gflags globals come from the environment; treat them as sources *)
-            true
-        | _
-         -> false )
     | Other, _
      -> (* Other matches everything *)
         true

infer/src/quandary/JavaTrace.ml

@@ -317,8 +317,6 @@ include Trace.Make (struct
   module Sink = JavaSink
 
   let should_report source sink =
-    if Source.is_footprint source then false
-    else
     match (Source.kind source, Sink.kind sink) with
       | PrivateData, Logging
       (* logging private data issue *)

infer/src/quandary/TaintAnalysis.ml

@@ -42,10 +42,7 @@ module Make (TaintSpecification : TaintSpec.S) = struct
        -> node_opt
       | None
        -> let make_footprint_trace footprint_ap =
-            let trace =
-              TraceDomain.of_source
-                (TraceDomain.Source.make_footprint footprint_ap proc_data.pdesc)
-            in
+            let trace = TraceDomain.of_footprint footprint_ap in
             Some (TaintDomain.make_normal_leaf trace)
           in
           let root, _ = AccessPath.Abs.extract access_path in

infer/src/unit/TraceTests.ml

@@ -118,13 +118,8 @@ let tests =
       let footprint_ap =
         AccessPath.Abs.Exact (AccessPath.of_id (Ident.create_none ()) (Typ.mk Tvoid))
       in
-      let dummy_pdesc =
-        Cfg.create_proc_desc (Cfg.create_cfg ())
-          (ProcAttributes.default Typ.Procname.empty_block !Config.curr_language)
-      in
-      let footprint_source = MockSource.make_footprint footprint_ap dummy_pdesc in
       let source_trace = MockTrace.of_source source1 in
-      let footprint_trace = MockTrace.of_source footprint_source |> MockTrace.add_sink sink1 in
+      let footprint_trace = MockTrace.of_footprint footprint_ap |> MockTrace.add_sink sink1 in
       let expected_trace = MockTrace.of_source source1 |> MockTrace.add_sink sink1 in
       assert_bool "Appended trace should contain source and sink"
         (trace_equal (MockTrace.append source_trace footprint_trace call_site) expected_trace)