[pulse] Revert back error message for general case of AccessToInvalidAddress

Summary: Error message was accidentally changed to a specific nullptr error message (D26887140 (cba144b779)) for any invalidation (use after delete, etc). This diff reverts back the error message for a general case and keeps the special case for nullptr dereference. Also fixed spacing for nullptr dereference error message.

Reviewed By: jvillard

Differential Revision: D27407628

fbshipit-source-id: 2649f3032

infer/src/pulse/PulseDiagnostic.ml

@@ -56,7 +56,34 @@ let immediate_or_first_call calling_context (trace : Trace.t) =
 let get_message diagnostic =
   let pulse_start_msg = "Pulse found a potential" in
   match diagnostic with
-  | AccessToInvalidAddress {calling_context; invalidation_trace; access_trace} ->
+  | AccessToInvalidAddress {calling_context; invalidation; invalidation_trace; access_trace} -> (
+    match invalidation with
+    | ConstantDereference i when IntLit.equal i IntLit.zero ->
+        (* Special error message for nullptr dereference *)
+        let pp_access_trace fmt (trace : Trace.t) =
+          match immediate_or_first_call calling_context trace with
+          | `Immediate ->
+              ()
+          | `Call f ->
+              F.fprintf fmt " in call to %a" CallEvent.describe f
+        in
+        let pp_invalidation_trace line fmt (trace : Trace.t) =
+          let pp_line fmt line = F.fprintf fmt "on line %d" line in
+          match immediate_or_first_call calling_context trace with
+          | `Immediate ->
+              F.fprintf fmt "null pointer dereference %a" pp_line line
+          | `Call f ->
+              F.fprintf fmt "null pointer dereference %a indirectly during the call to %a" pp_line
+                line CallEvent.describe f
+        in
+        let invalidation_line =
+          let {Location.line; _} = Trace.get_outer_location invalidation_trace in
+          line
+        in
+        F.asprintf "%s %a%a." pulse_start_msg
+          (pp_invalidation_trace invalidation_line)
+          invalidation_trace pp_access_trace access_trace
+    | _ ->
         (* The goal is to get one of the following messages depending on the scenario:
 
            42: delete x; return x->f
@@ -77,26 +104,26 @@ let get_message diagnostic =
         let pp_access_trace fmt (trace : Trace.t) =
           match immediate_or_first_call calling_context trace with
           | `Immediate ->
-            ()
+              F.fprintf fmt "accessing memory that "
           | `Call f ->
-            F.fprintf fmt "in call to %a " CallEvent.describe f
+              F.fprintf fmt "call to %a eventually accesses memory that " CallEvent.describe f
         in
-      let pp_invalidation_trace line fmt (trace : Trace.t) =
+        let pp_invalidation_trace line invalidation fmt (trace : Trace.t) =
           let pp_line fmt line = F.fprintf fmt " on line %d" line in
           match immediate_or_first_call calling_context trace with
           | `Immediate ->
-            F.fprintf fmt "null pointer dereference %a" pp_line line
+              F.fprintf fmt "%a%a" Invalidation.describe invalidation pp_line line
           | `Call f ->
-            F.fprintf fmt "null pointer dereference %a indirectly during the call to %a" pp_line
-              line CallEvent.describe f
+              F.fprintf fmt "%a%a indirectly during the call to %a" Invalidation.describe
+                invalidation pp_line line CallEvent.describe f
         in
         let invalidation_line =
           let {Location.line; _} = Trace.get_outer_location invalidation_trace in
           line
         in
-      F.asprintf "%s %a%a." pulse_start_msg
-        (pp_invalidation_trace invalidation_line)
-        invalidation_trace pp_access_trace access_trace
+        F.asprintf "%a%a" pp_access_trace access_trace
+          (pp_invalidation_trace invalidation_line invalidation)
+          invalidation_trace )
   | MemoryLeak {procname; location; allocation_trace} ->
       let allocation_line =
         let {Location.line; _} = Trace.get_outer_location allocation_trace in