summaryrefslogtreecommitdiff
path: root/src/rebar_agent.erl
blob: b4734f1653172c6703561c66af500a7a48e13edf (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
%%% @doc Runs a process that holds a rebar3 state and can be used
%%% to statefully maintain loaded project state into a running VM.
-module(rebar_agent).
-export([start_link/1, do/1, do/2, async_do/1, async_do/2]).
-export(['$handle_undefined_function'/2]).
-export([init/1,
         handle_call/3, handle_cast/2, handle_info/2,
         code_change/3, terminate/2]).

-include("rebar.hrl").

-record(state, {state,
                cwd,
                show_warning=true}).

%% @doc boots an agent server; requires a full rebar3 state already.
%% By default (within rebar3), this isn't called; `rebar_prv_shell'
%% enters and transforms into this module
-spec start_link(rebar_state:t()) -> {ok, pid()}.
start_link(State) ->
    gen_server:start_link({local, ?MODULE}, ?MODULE, State, []).

%% @doc runs a given command in the agent's context.
-spec do(atom()) -> ok | {error, term()}.
do(Command) when is_atom(Command) ->
    gen_server:call(?MODULE, {cmd, Command}, infinity);
do(Args) when is_list(Args) ->
    gen_server:call(?MODULE, {cmd, default, do, Args}, infinity).

%% @doc runs a given command in the agent's context, under a given
%% namespace.
-spec do(atom(), atom()) -> ok | {error, term()}.
do(Namespace, Command) when is_atom(Namespace), is_atom(Command) ->
    gen_server:call(?MODULE, {cmd, Namespace, Command}, infinity);
do(Namespace, Args) when is_atom(Namespace), is_list(Args) ->
    gen_server:call(?MODULE, {cmd, Namespace, do, Args}, infinity).

-spec async_do(atom()) -> ok | {error, term()}.
async_do(Command) when is_atom(Command) ->
    gen_server:cast(?MODULE, {cmd, Command});
async_do(Args) when is_list(Args) ->
    gen_server:cast(?MODULE, {cmd, default, do, Args}).

-spec async_do(atom(), atom()) -> ok.
async_do(Namespace, Command) when is_atom(Namespace), is_atom(Command) ->
    gen_server:cast(?MODULE, {cmd, Namespace, Command});
async_do(Namespace, Args) when is_atom(Namespace), is_list(Args) ->
    gen_server:cast(?MODULE, {cmd, Namespace, do, Args}).

'$handle_undefined_function'(Cmd, [Namespace, Args]) ->
    gen_server:call(?MODULE, {cmd, Namespace, Cmd, Args}, infinity);
'$handle_undefined_function'(Cmd, [Args]) ->
    gen_server:call(?MODULE, {cmd, default, Cmd, Args}, infinity);
'$handle_undefined_function'(Cmd, []) ->
    gen_server:call(?MODULE, {cmd, default, Cmd}, infinity).

%%%%%%%%%%%%%%%%%
%%% CALLBACKS %%%
%%%%%%%%%%%%%%%%%

%% @private
init(State) ->
    Cwd = rebar_dir:get_cwd(),
    {ok, #state{state=State, cwd=Cwd}}.

%% @private
handle_call({cmd, Command}, _From, State=#state{state=RState, cwd=Cwd}) ->
    MidState = maybe_show_warning(State),
    put(cmd_type, sync),
    {Res, NewRState} = run(default, Command, "", RState, Cwd),
    put(cmd_type, undefined),
    {reply, Res, MidState#state{state=NewRState}, hibernate};
handle_call({cmd, Namespace, Command}, _From, State = #state{state=RState, cwd=Cwd}) ->
    MidState = maybe_show_warning(State),
    put(cmd_type, sync),
    {Res, NewRState} = run(Namespace, Command, "", RState, Cwd),
    put(cmd_type, undefined),
    {reply, Res, MidState#state{state=NewRState}, hibernate};
handle_call({cmd, Namespace, Command, Args}, _From, State = #state{state=RState, cwd=Cwd}) ->
    MidState = maybe_show_warning(State),
    put(cmd_type, sync),
    {Res, NewRState} = run(Namespace, Command, Args, RState, Cwd),
    put(cmd_type, undefined),
    {reply, Res, MidState#state{state=NewRState}, hibernate};
handle_call(_Call, _From, State) ->
    {noreply, State}.

%% @private
handle_cast({cmd, Command}, State=#state{state=RState, cwd=Cwd}) ->
    MidState = maybe_show_warning(State),
    put(cmd_type, async),
    {_, NewRState} = run(default, Command, "", RState, Cwd),
    put(cmd_type, undefined),
    {noreply, MidState#state{state=NewRState}, hibernate};
handle_cast({cmd, Namespace, Command}, State = #state{state=RState, cwd=Cwd}) ->
    MidState = maybe_show_warning(State),
    put(cmd_type, async),
    {_, NewRState} = run(Namespace, Command, "", RState, Cwd),
    put(cmd_type, undefined),
    {noreply, MidState#state{state=NewRState}, hibernate};
handle_cast({cmd, Namespace, Command, Args}, State = #state{state=RState, cwd=Cwd}) ->
    MidState = maybe_show_warning(State),
    put(cmd_type, async),
    {_, NewRState} = run(Namespace, Command, Args, RState, Cwd),
    put(cmd_type, undefined),
    {noreply, MidState#state{state=NewRState}, hibernate};
handle_cast(_Cast, State) ->
    {noreply, State}.

%% @private
handle_info(_Info, State) ->
    {noreply, State}.

%% @private
code_change(_OldVsn, State, _Extra) ->
    {ok, State}.

%% @private
terminate(_Reason, _State) ->
    ok.

%%%%%%%%%%%%%%%
%%% PRIVATE %%%
%%%%%%%%%%%%%%%

%% @private runs the actual command and maintains the state changes
-spec run(atom(), atom(), string(), rebar_state:t(), file:filename()) ->
    {ok, rebar_state:t()} | {{error, term()}, rebar_state:t()}.
run(Namespace, Command, StrArgs, RState, Cwd) ->
    try
        case rebar_dir:get_cwd() of
            Cwd ->
                PArgs = getopt:tokenize(StrArgs),
                Args = [atom_to_list(Namespace), atom_to_list(Command)] ++ PArgs,
                CmdState0 = refresh_state(RState, Cwd),
                CmdState1 = rebar_state:set(CmdState0, task, atom_to_list(Command)),
                CmdState = rebar_state:set(CmdState1, caller, api),
                case rebar3:run(CmdState, Args) of
                    {ok, TmpState} ->
                        refresh_paths(TmpState),
                        {ok, CmdState};
                    {error, Err} when is_list(Err) ->
                        refresh_paths(CmdState),
                        {{error, lists:flatten(Err)}, CmdState};
                    {error, Err} ->
                        refresh_paths(CmdState),
                        {{error, Err}, CmdState}
                end;
            _ ->
                {{error, cwd_changed}, RState}
        end
    catch
        ?WITH_STACKTRACE(Type, Reason, Stacktrace)
            ?DEBUG("Agent Stacktrace: ~p", [Stacktrace]),
            {{error, {Type, Reason}}, RState}
    end.

%% @private function to display a warning for the feature only once
-spec maybe_show_warning(#state{}) -> #state{}.
maybe_show_warning(S=#state{show_warning=true}) ->
    ?WARN("This feature is experimental and may be modified or removed at any time.", []),
    S#state{show_warning=false};
maybe_show_warning(State) ->
    State.

%% @private based on a rebar3 state term, reload paths in a way
%% that makes sense.
-spec refresh_paths(rebar_state:t()) -> ok.
refresh_paths(RState) ->
    RefreshPaths = application:get_env(rebar, refresh_paths, [all_deps, test]),
    ToRefresh = parse_refresh_paths(RefreshPaths, RState, []),
    %% Modules from apps we can't reload without breaking functionality
    Blacklist = lists:usort(
        application:get_env(rebar, refresh_paths_blacklist, [])
        ++ [rebar, erlware_commons, providers, cf, cth_readable]),
    %% Similar to rebar_utils:update_code/1, but also forces a reload
    %% of used modules. Also forces to reload all of ebin/ instead
    %% of just the modules in the .app file, because 'extra_src_dirs'
    %% allows to load and compile files that are not to be kept
    %% in the app file.
    [refresh_path(Path, Blacklist) || Path <- ToRefresh],
    ok.

refresh_path(Path, Blacklist) ->
    Name = filename:basename(Path, "/ebin"),
    App = list_to_atom(Name),
    case App of
        test -> % skip
            code:add_patha(Path),
            ok;
        _ ->
            application:load(App),
            case application:get_key(App, modules) of
                undefined ->
                    code:add_patha(Path);
                {ok, _Mods} ->
                    case lists:member(App, Blacklist) of
                        false ->
                            refresh_path_do(Path, App);
                        true ->
                            ?DEBUG("skipping app ~p, stable copy required", [App])
                    end
            end
    end.
refresh_path_do(Path, App) ->
    Files = filelib:wildcard(filename:join([Path, "*.beam"])),
    Modules = [list_to_atom(filename:basename(F, ".beam"))
        || F <- Files],
    ?DEBUG("reloading ~p from ~ts", [Modules, Path]),
    code:replace_path(App, Path),
    reload_modules(Modules).

%% @private parse refresh_paths option
%% no_deps means only project_apps's ebin path
%% no_test means no test path
%% OtherPath.
parse_refresh_paths([all_deps | RefreshPaths], RState, Acc) ->
    Paths = rebar_state:code_paths(RState, all_deps),
    parse_refresh_paths(RefreshPaths, RState, Paths ++ Acc);
parse_refresh_paths([project_apps | RefreshPaths], RState, Acc) ->
    Paths = [filename:join([rebar_app_info:out_dir(App), "ebin"])
        || App <- rebar_state:project_apps(RState)],
    parse_refresh_paths(RefreshPaths, RState, Paths ++ Acc);
parse_refresh_paths([test | RefreshPaths], RState, Acc) ->
    Paths = [filename:join([rebar_app_info:out_dir(App), "test"])
        || App <- rebar_state:project_apps(RState)],
    parse_refresh_paths(RefreshPaths, RState, Paths ++ Acc);
parse_refresh_paths([RefreshPath0 | RefreshPaths], RState, Acc) when is_list(RefreshPath0) ->
    case filelib:is_dir(RefreshPath0) of
        true ->
            RefreshPath0 =
            case filename:basename(RefreshPath0) of
                "ebin" -> RefreshPath0;
                _ -> filename:join([RefreshPath0, "ebin"])
            end,
            parse_refresh_paths(RefreshPaths, RState, [RefreshPath0 | Acc]);
        false ->
            parse_refresh_paths(RefreshPaths, RState, Acc)
    end;
parse_refresh_paths([_ | RefreshPaths], RState, Acc) ->
    parse_refresh_paths(RefreshPaths, RState, Acc);
parse_refresh_paths([], _RState, Acc) ->
    lists:usort(Acc).

%% @private from a disk config, reload and reapply with the current
%% profiles; used to find changes in the config from a prior run.
-spec refresh_state(rebar_state:t(), file:filename()) -> rebar_state:t().
refresh_state(RState, _Dir) ->
    lists:foldl(
        fun(F, State) -> F(State) end,
        rebar3:init_config(),
        [fun(S) -> rebar_state:apply_profiles(S, rebar_state:current_profiles(RState)) end]
    ).

%% @private takes a list of modules and reloads them
-spec reload_modules([module()]) -> term().
reload_modules([]) -> noop;
reload_modules(Modules0) ->
    Modules = [M || M <- Modules0, is_changed(M)],
    reload_modules(Modules, erlang:function_exported(code, prepare_loading, 1)).

%% @spec is_changed(atom()) -> boolean()
%% @doc true if the loaded module is a beam with a vsn attribute
%%      and does not match the on-disk beam file, returns false otherwise.
is_changed(M) ->
    try
        module_vsn(M:module_info(attributes)) =/= module_vsn(code:get_object_code(M))
    catch _:_ ->
        false
    end.

module_vsn({M, Beam, _Fn}) ->
    % Because the vsn can set by -vsn(X) in module.
    % So didn't use beam_lib:version/1 to get the vsn.
    % So if set -vsn(X) in module, it will always reload the module.
    {ok, {M, <<Vsn:128>>}} = beam_lib:md5(Beam),
    Vsn;
module_vsn(Attrs) when is_list(Attrs) ->
    {_, Vsn} = lists:keyfind(vsn, 1, Attrs),
    Vsn.

%% @private reloading modules, when there are modules to actually reload
reload_modules(Modules, true) ->
    %% OTP 19 and later -- use atomic loading and ignore unloadable mods
    case code:prepare_loading(Modules) of
        {ok, Prepared} ->
            [code:purge(M) || M <- Modules],
            code:finish_loading(Prepared);
        {error, ModRsns} ->
            Blacklist =
                lists:foldr(fun({ModError, Error}, Acc) ->
                    case Error of
                        % perhaps cover other cases of failure?
                        on_load_not_allowed ->
                            reload_modules([ModError], false),
                            [ModError|Acc];
                        _ ->
                            ?DEBUG("Module ~p failed to atomic load because ~p", [ModError, Error]),
                            [ModError|Acc]
                    end
                end,
                [], ModRsns
            ),
            reload_modules(Modules -- Blacklist, true)
    end;
reload_modules(Modules, false) ->
    %% Older versions, use a more ad-hoc mechanism.
    lists:foreach(fun(M) ->
            code:delete(M),
            code:purge(M),
            case code:load_file(M) of
                {module, M} -> ok;
                {error, Error} ->
                    ?DEBUG("Module ~p failed to load because ~p", [M, Error])
            end
        end, Modules
    ).