Add `passage_default_tracer` compiler option
diff --git a/README.md b/README.md
index 0c187dc..8938c9f 100644
--- a/README.md
+++ b/README.md
@@ -65,6 +65,7 @@
-module(example).
-compile({parse_transform, passage_transform}). % Enables `passage_transform'
+-compile({passage_default_tracer, "foo_tracer"}). % Specifies the default tracer (optional)
-passage_trace([{tags, #{foo => "bar", size => "byte_size(Bin)"}}]).
-spec foo(binary()) -> binary().
diff --git a/src/passage_transform.erl b/src/passage_transform.erl
index 1a129b5..80dc844 100644
--- a/src/passage_transform.erl
+++ b/src/passage_transform.erl
@@ -12,6 +12,7 @@
%% -module(example).
%%
%% -compile({parse_transform, passage_transform}). % Enables `passage_transform'
+%% -compile({passage_default_tracer, "foo_tracer"}). % Specifies the default tracer (optional)
%%
%% -passage_trace([{tags, #{foo => "bar", size => "byte_size(Bin)"}}]).
%% -spec foo(binary()) -> binary().
@@ -127,6 +128,7 @@
application :: atom(),
module :: module(),
function :: atom(),
+ default_tracer :: expr_string() | undefined,
trace = false :: boolean(), % if `true' the next function will be traced
@@ -145,10 +147,13 @@
-spec parse_transform(AbstractForms, list()) -> AbstractForms when
AbstractForms :: [term()].
parse_transform(AbstractForms, CompileOptions) ->
- State = #state{
- application = guess_application(AbstractForms, CompileOptions),
- module = get_module(AbstractForms)
- },
+ DefaultTracer = proplists:get_value(passage_default_tracer, CompileOptions),
+ State =
+ #state{
+ application = guess_application(AbstractForms, CompileOptions),
+ module = get_module(AbstractForms),
+ default_tracer = DefaultTracer
+ },
walk_forms(AbstractForms, State).
%%------------------------------------------------------------------------------
@@ -160,9 +165,10 @@
lists:foldl(
fun ({attribute, _, passage_trace, Options}, {State0, Acc}) ->
Tracer =
- case lists:keyfind(tracer, 1, Options) of
- false -> error;
- {_, Id} -> {ok, Id}
+ case {lists:keyfind(tracer, 1, Options), State#state.default_tracer} of
+ {false, undefined} -> error;
+ {false, DefaultTracer} -> {ok, DefaultTracer};
+ {{_, Tracer0}, _} -> {ok, Tracer0}
end,
State1 =
State0#state{
