prints the jump destination address and name in the assembly output (#1469)

This is a simple quality of life update that should be done many years
ago. This change adds printing the jump destination address and name,
if present, in the assembly output, much like objdump does, e.g.,
```
c203: e8 70 7c ff ff            callq -0x8390 # 3e78 <malloc>
```

This commit also publishes the `Symtab.callee` function that gives this
information.

Author: ivg

lib/bap/bap.mli

@@ -7845,6 +7845,13 @@ module Std : sig
     (** [span fn] returns a memory map of a region occupied by a
         function [fn] *)
     val span : fn -> unit memmap
+
+    (** [explicit_callee symtab address] returns a callee which is
+        called from a  block with the given [address].
+
+        @since 2.5.0
+    *)
+    val callee : t -> addr -> string option
   end
 
   type lifter = mem -> Disasm_expert.Basic.full_insn -> bil Or_error.t

lib/bap_disasm/bap_disasm_symtab.ml

@@ -120,6 +120,10 @@ let insert_call ?(implicit=false) symtab block data =
 
 let explicit_callee {ecalls} = Map.find ecalls
 let implicit_callee {icalls} = Map.find icalls
+let callee tab src = match explicit_callee tab src with
+  | Some dst -> Some dst
+  | None -> implicit_callee tab src
+
 
 
 let (<--) = fun g f -> match g with

lib/bap_disasm/bap_disasm_symtab.mli

@@ -61,3 +61,5 @@ val explicit_callee : t -> addr -> string option
 (** [implicit_callee symtab address] returns a callee which is
     implicitly called from a block with the given [address]. *)
 val implicit_callee : t -> addr -> string option
+
+val callee : t -> addr -> string option

plugins/print/print_main.ml

@@ -369,7 +369,6 @@ let section_name memory start =
   function Some name -> name
          | None -> Format.asprintf ".section@%a" Addr.pp start
 
-
 let print_disasm pp_insn patterns ppf proj =
   let memory = Project.memory proj in
   let syms = Project.symbols proj in
@@ -389,19 +388,40 @@ let print_disasm pp_insn patterns ppf proj =
             sorted_blocks (Graphs.Cfg.nodes cfg) |> Seq.iter ~f:(fun blk ->
                 let mem = Block.memory blk in
                 fprintf ppf "%a:@\n" pp_addr (Memory.min_addr mem);
-                Block.insns blk |> List.iter ~f:(pp_insn ppf))));
+                Block.insns blk |> List.iter ~f:(pp_insn syms blk ppf))));
   pp_close_tbox ppf ()
 
-let pp_bil fmt ppf (mem,insn) =
+let pp_bil fmt _ _ ppf (mem,insn) =
   let pp_bil ppf = Bil.Io.print ~fmt ppf in
   let addr = Memory.min_addr mem in
   fprintf ppf "%a: %s@\n%a@\n" pp_addr addr (Insn.asm insn)
     pp_bil (Insn.bil insn)
 
-let pp_insn fmt ppf (mem,insn) =
+
+let jmp_dst insn =
+  let rec find = List.find_map ~f:(function
+      | Bil.Jmp (Int dst) ->  Some dst
+      | Bil.If (_,yay,nay) ->
+        Option.first_some (find yay) (find nay)
+      | _ -> None) in
+  find (Insn.bil insn)
+
+let print_jmp_dst tab blk ppf insn =
+  match jmp_dst insn, Symtab.callee tab (Block.addr blk) with
+  | Some dst, Some name ->
+    Format.fprintf ppf " # %s <%s>" (Addr.string_of_value dst) name
+  | Some dst, None ->
+    Format.fprintf ppf " # %s" (Addr.string_of_value dst)
+  | None, Some name ->
+    Format.fprintf ppf " # <%s>" name
+  | None, None -> ()
+
+let pp_insn fmt tab blk ppf (mem,insn) =
   Memory.pp ppf mem;
   pp_print_tab ppf ()  [@ocaml.warning "-3"];
   Insn.Io.print ~fmt ppf insn;
+  if phys_equal insn (Block.terminator blk)
+  then print_jmp_dst tab blk ppf insn;
   fprintf ppf "@\n"
 
 let pp_knowledge ppf _ =