fix dap configuration and add function break points

src/els_dap_general_provider.erl

@@ -64,6 +64,11 @@ init() ->
 
 -spec handle_request(request(), state()) -> {result(), state()}.
 handle_request({<<"initialize">>, _Params}, State) ->
+  %% quick fix to satisfy els_config initialization
+  {ok, RootPath} = file:get_cwd(),
+  RootUri = unicode:characters_to_binary(["file://", RootPath]),
+  InitOptions = #{},
+  ok = els_config:initialize(RootUri, capabilities(), InitOptions),
   {capabilities(), State};
 handle_request({<<"launch">>, Params}, State) ->
   #{<<"cwd">> := Cwd} = Params,
@@ -138,6 +143,7 @@ handle_request( {<<"setBreakpoints">>, Params}
   els_distribution_server:wait_connect_and_monitor(ProjectNode),
 
   %% TODO: Keep a list of interpreted modules, not to re-interpret them
+  els_dap_rpc:no_break(ProjectNode),
   els_dap_rpc:i(ProjectNode, Module),
   [els_dap_rpc:break(ProjectNode, Module, Line) ||
     #{<<"line">> := Line} <- SourceBreakpoints],
@@ -146,6 +152,34 @@ handle_request( {<<"setBreakpoints">>, Params}
   {#{<<"breakpoints">> => Breakpoints}, State};
 handle_request({<<"setExceptionBreakpoints">>, _Params}, State) ->
   {#{}, State};
+handle_request({<<"setFunctionBreakpoints">>, Params}
+              , #{project_node := ProjectNode} = State
+              ) ->
+  FunctionBreakPoints = maps:get(<<"breakpoints">>, Params, []),
+  els_distribution_server:wait_connect_and_monitor(ProjectNode),
+
+  els_dap_rpc:no_break(ProjectNode),
+  MFAs = [
+    begin
+      Spec = {Mod, _, _} = parse_mfa(MFA),
+      els_dap_rpc:i(ProjectNode, Mod),
+      Spec
+      end
+       ||
+    #{<<"name">> := MFA, <<"enabled">>:= Enabled} <- FunctionBreakPoints,
+    Enabled andalso parse_mfa(MFA) =/= error
+  ],
+  [ els_dap_rpc:break_in(ProjectNode, Mod, Func, Arity)
+    || {Mod, Func, Arity} <- MFAs
+  ],
+  Breakpoints =
+    [ #{ <<"verified">> => true
+      ,  <<"line">>     => Line
+      , <<"source">>    => #{ <<"path">> => source(Module, ProjectNode)}}
+    || {{Module, Line}, [Status, _, _, _]}
+        <- els_dap_rpc:all_breaks(ProjectNode)
+    , Status =:= active],
+  {#{<<"breakpoints">> => Breakpoints}, State};
 handle_request({<<"threads">>, _Params}, #{threads := Threads0} = State) ->
   Threads =
     [ #{ <<"id">> => Id
@@ -256,7 +290,8 @@ handle_info( {int_cb, ThreadPid}
 -spec capabilities() -> capabilities().
 capabilities() ->
   #{ <<"supportsConfigurationDoneRequest">> => true
-   , <<"supportsEvaluateForHovers">> => true }.
+   , <<"supportsEvaluateForHovers">> => true
+   , <<"supportsFunctionBreakpoints">> => true}.
 
 %%==============================================================================
 %% Internal Functions
@@ -316,3 +351,25 @@ frame_by_id(FrameId, Threads) ->
 -spec format_mfa(module(), atom(), integer()) -> binary().
 format_mfa(M, F, A) ->
   els_utils:to_binary(io_lib:format("~p:~p/~p", [M, F, A])).
+
+-spec parse_mfa(string()) -> {module(), atom(), non_neg_integer()} | error.
+parse_mfa(MFABinary) ->
+  MFA = unicode:characters_to_list(MFABinary),
+  ?LOG_DEBUG("tokens for ~p: ~w", [MFA,  erl_scan:string(MFA)]),
+  case erl_scan:string(MFA) of
+    {ok, [ {'fun', _}
+         , {atom, _, Module}
+         , {':', _}
+         , {atom, _, Function}
+         , {'/', _}
+         , {integer, _, Arity}], _} when Arity >= 0 ->
+      {Module, Function, Arity};
+    {ok, [ {atom, _, Module}
+         , {':', _}
+         , {atom, _, Function}
+         , {'/', _}
+         , {integer, _, Arity}], _} when Arity >= 0 ->
+      {Module, Function, Arity};
+    _ ->
+      error
+  end.

src/els_dap_rpc.erl

@@ -1,7 +1,9 @@
 -module(els_dap_rpc).
 
--export([ auto_attach/3
+-export([ all_breaks/1
+        , auto_attach/3
         , break/3
+        , break_in/4
         , continue/2
         , eval/3
         , get_meta/2
@@ -10,11 +12,17 @@
         , meta/4
         , module_info/3
         , next/2
+        , no_break/1
         , snapshot/1
         , stack_trace/2
         , step/2
         ]).
 
+
+-spec all_breaks(node()) -> any().
+all_breaks(Node) ->
+  rpc:call(Node, int, all_breaks, []).
+
 -spec auto_attach(node(), [atom()], {module(), atom(), [any()]}) -> any().
 auto_attach(Node, Flags, MFA) ->
   rpc:call(Node, int, auto_attach, [Flags, MFA]).
@@ -23,6 +31,10 @@ auto_attach(Node, Flags, MFA) ->
 break(Node, Module, Line) ->
   rpc:call(Node, int, break, [Module, Line]).
 
+-spec break_in(node(), module(), atom(), non_neg_integer()) -> any().
+break_in(Node, Module, Func, Arity) ->
+  rpc:call(Node, int, break_in, [ Module, Func, Arity]).
+
 -spec continue(node(), pid()) -> any().
 continue(Node, Pid) ->
   rpc:call(Node, int, continue, [Pid]).
@@ -57,6 +69,10 @@ meta(Node, Meta, Flag, Opt) ->
 next(Node, Pid) ->
   rpc:call(Node, int, next, [Pid]).
 
+-spec no_break(node()) -> ok.
+no_break(Node) ->
+  rpc:call(Node, int, no_break, []).
+
 -spec module_info(node(), module(), atom()) -> any().
 module_info(Node, Module, What) ->
   rpc:call(Node, Module, module_info, [What]).

src/els_dap_sup.erl

@@ -50,7 +50,11 @@ init([]) ->
   ?LOG_INFO("Starting session (version ~p)", [Vsn]),
   %% Restrict access to stdio when using that transport
   restrict_stdio_access(Transport),
-  ChildSpecs = [ #{ id    => els_dap_providers_sup
+  ChildSpecs = [ #{ id       => els_config
+                  , start    => {els_config, start_link, []}
+                  , shutdown => brutal_kill
+                  }
+               , #{ id    => els_dap_providers_sup
                   , start => {els_dap_providers_sup, start_link, []}
                   , type  => supervisor
                   }