1 files changed, 59 insertions, 0 deletions
diff --git a/erts/preloaded/src/erl_tracer.erl b/erts/preloaded/src/erl_tracer.erl
new file mode 100644
index 0000000000..de1e9ca01e
--- /dev/null
+++ b/erts/preloaded/src/erl_tracer.erl
@@ -0,0 +1,59 @@
+-module(erl_tracer).
+
+-export([enabled/3, trace/6, on_load/0]).
+
+-type tracee() :: port() | pid() | undefined.
+
+-type trace_tag_running_ports() :: in | out | in_exiting | out_exiting | out_exited.
+-type trace_tag_running_procs() :: in | out | in_exiting | out_exiting | out_exited.
+-type trace_tag_send() :: send | send_to_non_existing_process.
+-type trace_tag_receive() :: 'receive'.
+-type trace_tag_call() :: call | return_to | return_from | exception_from.
+-type trace_tag_procs() :: spawn | spawned | exit | link | unlink
+                         | getting_linked | getting_unlinked
+                         | register | unregister.
+-type trace_tag_ports() :: open | closed  | link | unlink
+                         | getting_linked | getting_unlinked.
+-type trace_tag_gc() :: gc_minor_start | gc_minor_end
+                      | gc_major_start | gc_major_end.
+
+-type trace_tag() :: trace_tag_send()
+                   | trace_tag_receive()
+                   | trace_tag_call()
+                   | trace_tag_procs()
+                   | trace_tag_ports()
+                   | trace_tag_running_procs()
+                   | trace_tag_running_ports()
+                   | trace_tag_gc().
+
+-type trace_opts() :: #{ match_spec_result => true | term(),
+                         scheduler_id => undefined | non_neg_integer(),
+                         timestamp => undefined | timestamp | cpu_timestamp |
+                                      monotonic | strict_monotonic }.
+-type tracer_state() :: term().
+
+on_load() ->
+    case erlang:load_nif(atom_to_list(?MODULE), 0) of
+        ok -> ok
+    end.
+
+%%%
+%%% NIF placeholders
+%%%
+
+-spec enabled(Tag :: trace_tag() | seq_trace | trace_status,
+              TracerState :: tracer_state(),
+              Tracee :: tracee()) ->
+   trace | discard | remove.
+enabled(_, _, _) ->
+    erlang:nif_error(nif_not_loaded).
+
+-spec trace(Tag :: trace_tag() | seq_trace,
+            TracerState :: tracer_state(),
+            Tracee :: tracee(),
+            Msg :: term(),
+            Extra :: term(),
+            Opts :: trace_opts()) -> any().
+
+trace(_, _, _, _, _, _) ->
+    erlang:nif_error(nif_not_loaded).