[preanalysis] expose separate functions for different preanalyes (liveness, dynamic dispatch, abstraction)

Summary: Different analyses need different preanalyses to run. It doesn't make sense for all of the pre-analyses to be bundled together into one package.

Reviewed By: jvillard

Differential Revision: D4348243

fbshipit-source-id: 46a8ebd

infer/src/backend/interproc.ml

@@ -1478,11 +1478,15 @@ let do_analysis exe_env =
     let analyze_ondemand source proc_desc =
       let proc_name = Procdesc.get_proc_name proc_desc in
       let tenv = Exe_env.get_tenv exe_env proc_name in
-      if not (Config.eradicate || Config.checkers)
+      if not (Config.eradicate || Config.checkers) && not (Procdesc.did_preanalysis proc_desc)
       then
         (* Eradicate and the checkers don't need the Nullify/Remove_temps/Abstract instructions that
            the preanalysis inserts. *)
-        Preanal.doit proc_desc (Exe_env.get_cg exe_env) tenv;
+        begin
+          Preanal.do_liveness proc_desc tenv;
+          Preanal.do_abstraction proc_desc;
+          Preanal.do_dynamic_dispatch proc_desc (Exe_env.get_cg exe_env) tenv `None
+        end;
       let summaryfp =
         Config.run_in_footprint_mode (analyze_proc source exe_env) proc_desc in
       Specs.add_summary proc_name summaryfp;

infer/src/backend/preanal.ml

@@ -11,11 +11,12 @@
 open! IStd
 
 (** mutate the cfg/cg to add dynamic dispatch handling *)
-let add_dispatch_calls pdesc cg tenv ~handle_dynamic_dispatch =
+let add_dispatch_calls pdesc cg tenv policy =
+  let sound_dynamic_dispatch = policy = `Sound in
   let node_add_dispatch_calls caller_pname node =
     let call_flags_is_dispatch call_flags =
       (* if sound dispatch is turned off, only consider dispatch for interface calls *)
-      (handle_dynamic_dispatch && call_flags.CallFlags.cf_virtual) ||
+      (sound_dynamic_dispatch && call_flags.CallFlags.cf_virtual) ||
       call_flags.CallFlags.cf_interface in
     let instr_is_dispatch_call = function
       | Sil.Call (_, _, _, _, call_flags) -> call_flags_is_dispatch call_flags
@@ -39,7 +40,7 @@ let add_dispatch_calls pdesc cg tenv ~handle_dynamic_dispatch =
           (match sorted_overrides with
            | ((_, target_pname) :: _) as all_targets ->
                let targets_to_add =
-                 if handle_dynamic_dispatch then
+                 if sound_dynamic_dispatch then
                    IList.map snd all_targets
                  else
                    (* if sound dispatch is turned off, consider only the first target. we do this
@@ -302,19 +303,17 @@ let do_copy_propagation pdesc tenv =
 
 let do_liveness pdesc tenv =
   let liveness_proc_cfg = BackwardCfg.from_pdesc pdesc in
-  LivenessAnalysis.exec_cfg liveness_proc_cfg (ProcData.make_default pdesc tenv)
-
-let doit ?(handle_dynamic_dispatch= (Config.dynamic_dispatch = `Sound)) pdesc cg tenv =
-  if not (Procdesc.did_preanalysis pdesc)
-  then
-    begin
-      Procdesc.signal_did_preanalysis pdesc;
+  let liveness_inv_map =
+    LivenessAnalysis.exec_cfg liveness_proc_cfg (ProcData.make_default pdesc tenv) in
   if Config.copy_propagation then do_copy_propagation pdesc tenv;
-      let liveness_inv_map = do_liveness pdesc tenv in
-      if Config.dynamic_dispatch <> `Lazy && Config.copy_propagation
-      then remove_dead_frontend_stores pdesc liveness_inv_map;
   add_nullify_instrs pdesc tenv liveness_inv_map;
-      if Config.dynamic_dispatch <> `Lazy
-      then add_dispatch_calls ~handle_dynamic_dispatch pdesc cg tenv;
+  Procdesc.signal_did_preanalysis pdesc
+
+let do_abstraction pdesc =
   add_abstraction_instructions pdesc;
-    end
+  Procdesc.signal_did_preanalysis pdesc
+
+let do_dynamic_dispatch pdesc cg tenv policy =
+  if policy <> `Lazy
+  then add_dispatch_calls pdesc cg tenv policy;
+  Procdesc.signal_did_preanalysis pdesc

infer/src/backend/preanal.mli

@@ -10,7 +10,15 @@
 
 open! IStd
 
-(** Preanalysis for eliminating dead local variables *)
+(** Various preanalysis passes for transforming the IR in useful ways *)
 
-(** Perform liveness analysis *)
-val doit : ?handle_dynamic_dispatch:bool -> Procdesc.t -> Cg.t -> Tenv.t -> unit
+(** perform liveness analysis and insert Nullify/Remove_temps instructions into the IR to make it
+    easy for analyses to do abstract garbage collection *)
+val do_liveness : Procdesc.t -> Tenv.t -> unit
+
+(** add Abstract instructions into the IR to give hints about when abstraction should be
+    performed *)
+val do_abstraction : Procdesc.t -> unit
+
+(** add possible dynamic dispatch targets to the call_flags of each call site *)
+val do_dynamic_dispatch : Procdesc.t -> Cg.t -> Tenv.t -> Config.dynamic_dispatch_policy -> unit

infer/src/base/Config.ml

@@ -215,6 +215,11 @@ let whitelisted_cpp_classes = [
   ["std"; "__normal_iterator"]; (* libstdc++ internal name of vector iterator *)
 ]
 
+type dynamic_dispatch_policy = [
+  | `Lazy
+  | `Sound
+  | `None
+]
 
 (** Compile time configuration values *)
 

infer/src/base/Config.mli

@@ -35,6 +35,11 @@ val ml_bucket_symbols :
 
 type os_type = Unix | Win32 | Cygwin
 
+type dynamic_dispatch_policy = [
+  | `Lazy
+  | `Sound
+  | `None
+]
 
 (** Constant configuration values *)
 

infer/src/quandary/TaintAnalysis.ml

@@ -517,7 +517,12 @@ module Make (TaintSpecification : TaintSpec.S) = struct
   let checker callback =
 
     let compute_post (proc_data : formal_map ProcData.t) =
-      Preanal.doit ~handle_dynamic_dispatch:true proc_data.pdesc (Cg.create None) proc_data.tenv;
+      if not (Procdesc.did_preanalysis proc_data.pdesc)
+      then
+        begin
+          Preanal.do_liveness proc_data.pdesc proc_data.tenv;
+          Preanal.do_dynamic_dispatch proc_data.pdesc (Cg.create None) proc_data.tenv `Sound;
+        end;
       match Analyzer.compute_post proc_data with
       | Some { access_tree; } ->
           Some (make_summary proc_data.extras access_tree)