Add support for "pause" request

Summary: We implement the "pause" request. The request takes a threadId, but we ignore it and just pause every process (similar to what we do with "continue").

Reviewed By: thizanne

Differential Revision: D68790443

fbshipit-source-id: 4e0f613b76ac6859167515812dc6d25ecb200f54

rebar.config

@@ -66,6 +66,8 @@
     {ct, "mkdir -p _build/test/lib/edb/test/edb_main_SUITE_data"},
     {ct, "cp _build/default/bin/edb _build/test/lib/edb/test/edb_main_SUITE_data"},
     {ct, "mkdir -p _build/test/lib/edb/test/edb_dap_scopes_SUITE_data"},
+    {ct, "mkdir -p _build/test/lib/edb/test/edb_dap_pause_SUITE_data"},
+    {ct, "cp _build/default/bin/edb _build/test/lib/edb/test/edb_dap_pause_SUITE_data"}
     {ct, "cp _build/default/bin/edb _build/test/lib/edb/test/edb_dap_scopes_SUITE_data"},
     {ct, "mkdir -p _build/test/lib/edb/test/edb_dap_session_SUITE_data"},
     {ct, "cp _build/default/bin/edb _build/test/lib/edb/test/edb_dap_session_SUITE_data"},

src/edb_dap.erl

@@ -64,6 +64,8 @@
     message/0,
     next_request_arguments/0,
     next_response/0,
+    pause_request_arguments/0,
+    pause_response/0,
     protocol_message_type/0,
     protocol_message/0,
     request/0,
@@ -390,6 +392,18 @@ build_error_response(Id, Format) ->
     presentationHint => binary()
 }.
 
+%%% Pause
+%%% https://microsoft.github.io/debug-adapter-protocol/specification#Requests_Pause
+-type pause_request_arguments() :: #{
+    % Pause execution for this thread.
+    threadId := thread_id()
+}.
+-type pause_response() :: #{
+    success := boolean(),
+    message => binary(),
+    body := #{}
+}.
+
 %%% Continue
 %%% https://microsoft.github.io/debug-adapter-protocol/specification#Requests_Continue
 -type continue_request_arguments() :: #{

src/edb_dap_events.erl

@@ -77,7 +77,14 @@ stopped(_State, {step, Pid}) ->
         threadId => edb_dap_id_mappings:pid_to_thread_id(Pid),
         allThreadsStopped => true
     },
-    #{actions => [{event, <<"stopped">>, StoppedEventBody}]};
+    #{actions => [{event, ~"stopped", StoppedEventBody}]};
+stopped(_State, pause) ->
+    StoppedEventBody = #{
+        reason => ~"pause",
+        preserveFocusHint => true,
+        allThreadsStopped => true
+    },
+    #{actions => [{event, ~"stopped", StoppedEventBody}]};
 stopped(_State, Event) ->
     ?LOG_WARNING("Skipping stopped event: ~p", [Event]),
     #{}.

src/edb_dap_requests.erl

@@ -28,7 +28,7 @@
 -include_lib("kernel/include/logger.hrl").
 
 -export([initialize/2, launch/2, disconnect/2]).
--export([set_breakpoints/2, continue/2, next/2, step_out/2]).
+-export([set_breakpoints/2, pause/2, continue/2, next/2, step_out/2]).
 -export([threads/2, stack_trace/2, scopes/2, variables/2]).
 
 -type reaction(T) :: #{
@@ -387,6 +387,12 @@ stack_frames(State, ThreadId) ->
             []
     end.
 
+-spec pause(edb_dap_state:t(), edb_dap:pause_request_arguments()) ->
+    reaction(edb_dap:pause_response()).
+pause(_State, _Args) ->
+    ok = edb:pause(),
+    #{response => #{success => true, body => #{}}}.
+
 -spec continue(edb_dap_state:t(), edb_dap:continue_request_arguments()) ->
     reaction(edb_dap:continue_response()).
 continue(_State, _Args) ->

src/edb_dap_server.erl

@@ -281,30 +281,32 @@ dispatch_event(Event, _DAPState) ->
 %% @doc Explicit mapping to avoid the risk of atom exhaustion
 -spec method_to_atom(binary()) -> atom().
 % Requests
-method_to_atom(<<"initialize">>) ->
+method_to_atom(~"initialize") ->
     initialize;
-method_to_atom(<<"launch">>) ->
+method_to_atom(~"launch") ->
     launch;
-method_to_atom(<<"disconnect">>) ->
+method_to_atom(~"disconnect") ->
     disconnect;
-method_to_atom(<<"setBreakpoints">>) ->
+method_to_atom(~"setBreakpoints") ->
     set_breakpoints;
-method_to_atom(<<"threads">>) ->
+method_to_atom(~"threads") ->
     threads;
-method_to_atom(<<"stackTrace">>) ->
+method_to_atom(~"stackTrace") ->
     stack_trace;
-method_to_atom(<<"continue">>) ->
+method_to_atom(~"pause") ->
+    pause;
+method_to_atom(~"continue") ->
     continue;
-method_to_atom(<<"next">>) ->
+method_to_atom(~"next") ->
     next;
-method_to_atom(<<"stepOut">>) ->
+method_to_atom(~"stepOut") ->
     step_out;
-method_to_atom(<<"scopes">>) ->
+method_to_atom(~"scopes") ->
     scopes;
-method_to_atom(<<"variables">>) ->
+method_to_atom(~"variables") ->
     variables;
 % Reverse requests
-method_to_atom(<<"runInTerminal">>) ->
+method_to_atom(~"runInTerminal") ->
     run_in_terminal;
 method_to_atom(Method) ->
     ?LOG_WARNING("Method not found: ~p", [Method]),

test/edb_dap_pause_SUITE.erl

@@ -0,0 +1,120 @@
+%% Copyright (c) Meta Platforms, Inc. and affiliates.
+%%
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
+%%
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
+%% % @format
+
+%% Pause/continue for the EDB DAP adapter
+
+-module(edb_dap_pause_SUITE).
+
+%% erlfmt:ignore
+% @fb-only
+
+% @fb-only
+-include_lib("stdlib/include/assert.hrl").
+
+%% CT callbacks
+-export([
+    all/0,
+    init_per_testcase/2,
+    end_per_testcase/2
+]).
+
+%% Test cases
+-export([
+    test_can_pause_and_continue/1
+]).
+
+all() ->
+    [
+        test_can_pause_and_continue
+    ].
+
+init_per_testcase(_TestCase, Config) ->
+    Config.
+
+end_per_testcase(_TestCase, _Config) ->
+    edb_test_support:stop_all_peer_nodes(),
+    ok.
+
+%%--------------------------------------------------------------------
+%% TEST CASES
+%%--------------------------------------------------------------------
+test_can_pause_and_continue(Config) ->
+    {ok, Peer, Node, Cookie} = edb_test_support:start_peer_node(Config, "debuggee"),
+    {ok, Client, _Cwd} = edb_dap_test_support:start_session(Config, Node, Cookie),
+    ModuleSource = erlang:iolist_to_binary([
+        ~"-module(foo).               %L01\n",
+        ~"-export([go/0]).            %L02\n",
+        ~"go() ->                     %L03\n",
+        ~"    timer:sleep(infinity),  %L04\n",
+        ~"    ok.                     %L05\n"
+    ]),
+    {ok, ThreadId, ST0} = edb_dap_test_support:ensure_process_in_bp(
+        Config, Client, Peer, {source, ModuleSource}, go, [], {line, 4}
+    ),
+
+    % Sanity-check: we are on line 4
+    ?assertMatch([#{name := ~"foo:go/0", line := 4} | _], ST0),
+
+    % Continue!
+    ContinueResponse = edb_dap_test_client:continue(Client, ThreadId),
+    ?assertMatch(
+        #{
+            command := ~"continue",
+            type := response,
+            success := true,
+            body := #{
+                allThreadsContinued := true
+            }
+        },
+        ContinueResponse
+    ),
+
+    % Pause!
+    PauseResponse = edb_dap_test_client:pause(Client, ThreadId),
+    EmptyBody = #{},
+    ?assertMatch(
+        #{
+            command := ~"pause",
+            type := response,
+            success := true,
+            body := EmptyBody
+        },
+        PauseResponse
+    ),
+
+    wait_for_stopped_event_with_pause_reason(Client),
+
+    ok.
+
+%%--------------------------------------------------------------------
+%% Helpers
+%% -------------------------------------------------------------------
+
+-spec wait_for_stopped_event_with_pause_reason(Client) -> ok when
+    Client :: edb_dap_test_client:client().
+wait_for_stopped_event_with_pause_reason(Client) ->
+    {ok, [StoppedEvent]} = edb_dap_test_client:wait_for_event(~"stopped", Client),
+    ?assertMatch(
+        #{
+            event := ~"stopped",
+            body := #{
+                reason := ~"pause",
+                preserveFocusHint := true,
+                allThreadsStopped := true
+            }
+        },
+        StoppedEvent
+    ),
+    ok.

test/edb_dap_test_client.erl

@@ -36,6 +36,7 @@
     set_breakpoints/2,
     threads/2,
     stack_trace/2,
+    pause/2,
     continue/2,
     next/2,
     step_out/2,
@@ -96,6 +97,11 @@ stack_trace(Client, Args) ->
     Request = #{type => request, command => <<"stackTrace">>, arguments => Args},
     gen_server:call(Client, Request).
 
+-spec pause(client(), edb_dap:pause_request_arguments()) -> ok.
+pause(Client, Args) ->
+    Request = #{type => request, command => <<"pause">>, arguments => Args},
+    gen_server:call(Client, Request).
+
 -spec continue(client(), edb_dap:continue_request_arguments()) -> ok.
 continue(Client, Args) ->
     Request = #{type => request, command => <<"continue">>, arguments => Args},