ocaml/toplevel/trace.ml

98 lines
3.1 KiB
OCaml

(***********************************************************************)
(* *)
(* Objective Caml *)
(* *)
(* Xavier Leroy, projet Cristal, INRIA Rocquencourt *)
(* *)
(* Copyright 1996 Institut National de Recherche en Informatique et *)
(* Automatique. Distributed only by permission. *)
(* *)
(***********************************************************************)
(* $Id$ *)
(* The "trace" facility *)
open Format
open Misc
open Longident
open Typedtree
open Printval
open Toploop
type traced_function =
{ path: Path.t;
closure: Obj.t;
initial_closure: Obj.t;
instrumented_fun: Obj.t }
let traced_functions = ref ([] : traced_function list)
(* Check if a function is already traced *)
let is_traced clos =
let rec is_traced = function
[] -> None
| tf :: rem -> if tf.closure == clos then Some tf.path else is_traced rem
in is_traced !traced_functions
(* Make a copy of a closure *)
let copy_closure cls =
let sz = Obj.size cls in
let nw = Obj.new_block 250 sz in
for i = 0 to sz - 1 do Obj.set_field nw i (Obj.field cls i) done;
nw
(* Overwrite the code field of a closure by another *)
let overwrite_closure dst src =
Obj.set_field dst 0 (Obj.field src 0)
(* Return a closure that performs as the given closure, but also
traces its execution. *)
let rec instrument_closure name clos_typ =
match (Ctype.repr clos_typ).desc with
Tarrow(t1, t2) ->
let starred_name =
match name with
Lident s -> Lident(s ^ "*")
| Ldot(lid, s) -> Ldot(lid, s ^ "*")
| Lapply(l1, l2) -> fatal_error "Trace.instrument_closure" in
let trace_res = instrument_closure starred_name t2 in
(fun clos_val ->
Obj.repr(fun arg ->
open_hovbox 2;
Printtyp.longident name; print_string " <--"; print_space();
print_value !toplevel_env arg t1; close_box(); print_newline();
try
let res = (Obj.magic clos_val : Obj.t -> Obj.t)(arg) in
open_hovbox 2;
Printtyp.longident name; print_string " -->"; print_space();
print_value !toplevel_env res t2; close_box(); print_newline();
trace_res res
with exn ->
open_hovbox 2;
Printtyp.longident name; print_string " raises"; print_space();
print_exception (Obj.repr exn); close_box(); print_newline();
raise exn))
| _ ->
(fun v -> v)
(* Given the address of a closure, find its instrumented version
and call it *)
let rec find_traced_closure clos = function
[] ->
fatal_error "Trace.find_traced_closure"
| f :: rem ->
if f.closure == clos then f else find_traced_closure clos rem
let print_trace clos arg =
(Obj.magic
(find_traced_closure clos !traced_functions).instrumented_fun :
Obj.t -> Obj.t)
arg