aboutsummaryrefslogtreecommitdiffstats
path: root/lib/typer/src/typer.erl
blob: 3bff546243e4ce2c83c2c33f4c37d5649c2d0a2a (plain) (blame)
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
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
%% -*- erlang-indent-level: 2 -*-
%%
%% 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.

%%-----------------------------------------------------------------------
%% File        : typer.erl
%% Author(s)   : The first version of typer was written by Bingwen He
%%               with guidance from Kostis Sagonas and Tobias Lindahl.
%%               Since June 2008 typer is maintained by Kostis Sagonas.
%% Description : An Erlang/OTP application that shows type information
%%               for Erlang modules to the user.  Additionally, it can
%%               annotate the code of files with such type information.
%%-----------------------------------------------------------------------

-module(typer).

-export([start/0]).

%%-----------------------------------------------------------------------

-define(SHOW, show).
-define(SHOW_EXPORTED, show_exported).
-define(ANNOTATE, annotate).
-define(ANNOTATE_INC_FILES, annotate_inc_files).

-type mode() :: ?SHOW | ?SHOW_EXPORTED | ?ANNOTATE | ?ANNOTATE_INC_FILES.

%%-----------------------------------------------------------------------

-type files()      :: [file:filename()].
-type callgraph()  :: dialyzer_callgraph:callgraph().
-type codeserver() :: dialyzer_codeserver:codeserver().
-type plt()        :: dialyzer_plt:plt().

-record(analysis,
	{mode				 :: mode() | 'undefined',
	 macros     = []		 :: [{atom(), term()}],
	 includes   = []		 :: files(),
	 codeserver = dialyzer_codeserver:new():: codeserver(),
	 callgraph  = dialyzer_callgraph:new() :: callgraph(),
	 files      = []		 :: files(),   % absolute names
	 plt        = none		 :: 'none' | file:filename(),
	 no_spec    = false              :: boolean(),
	 show_succ  = false              :: boolean(),
	 %% For choosing between specs or edoc @spec comments
	 edoc       = false		 :: boolean(),
	 %% Files in 'fms' are compilable with option 'to_pp'; we keep them
	 %% as {FileName, ModuleName} in case the ModuleName is different
	 fms        = []		 :: [{file:filename(), module()}],
	 ex_func    = map__new()	 :: map_dict(),
	 record     = map__new()	 :: map_dict(),
	 func       = map__new()	 :: map_dict(),
	 inc_func   = map__new()	 :: map_dict(),
	 trust_plt  = dialyzer_plt:new() :: plt()}).
-type analysis() :: #analysis{}.

-record(args, {files   = [] :: files(),
	       files_r = [] :: files(),
	       trusted = [] :: files()}).
-type args() :: #args{}.

%%--------------------------------------------------------------------

-spec start() -> no_return().

start() ->
  {Args, Analysis} = process_cl_args(),
  %% io:format("Args: ~p\n", [Args]),
  %% io:format("Analysis: ~p\n", [Analysis]),
  Timer = dialyzer_timing:init(false),
  TrustedFiles = filter_fd(Args#args.trusted, [], fun is_erl_file/1),
  Analysis2 = extract(Analysis, TrustedFiles),
  All_Files = get_all_files(Args),
  %% io:format("All_Files: ~p\n", [All_Files]),
  Analysis3 = Analysis2#analysis{files = All_Files},
  Analysis4 = collect_info(Analysis3),
  %% io:format("Final: ~p\n", [Analysis4#analysis.fms]),
  TypeInfo = get_type_info(Analysis4),
  dialyzer_timing:stop(Timer),
  show_or_annotate(TypeInfo),
  %% io:format("\nTyper analysis finished\n"),
  erlang:halt(0).

%%--------------------------------------------------------------------

-spec extract(analysis(), files()) -> analysis().

extract(#analysis{macros = Macros,
		  includes = Includes,
		  trust_plt = TrustPLT} = Analysis, TrustedFiles) ->
  %% io:format("--- Extracting trusted typer_info... "),
  Ds = [{d, Name, Value} || {Name, Value} <- Macros],
  CodeServer = dialyzer_codeserver:new(),
  Fun =
    fun(File, CS) ->
	%% We include one more dir; the one above the one we are trusting
	%% E.g, for /home/tests/typer_ann/test.ann.erl, we should include
	%% /home/tests/ rather than /home/tests/typer_ann/
	AllIncludes = [filename:dirname(filename:dirname(File)) | Includes],
	Is = [{i, Dir} || Dir <- AllIncludes],
	CompOpts = dialyzer_utils:src_compiler_opts() ++ Is ++ Ds,
	case dialyzer_utils:get_abstract_code_from_src(File, CompOpts) of
	  {ok, AbstractCode} -> 
	    case dialyzer_utils:get_record_and_type_info(AbstractCode) of
	      {ok, RecDict} ->
		Mod = list_to_atom(filename:basename(File, ".erl")),
		case dialyzer_utils:get_spec_info(Mod, AbstractCode, RecDict) of
		  {ok, SpecDict, CbDict} ->
		    CS1 = dialyzer_codeserver:store_temp_records(Mod, RecDict, CS),
		    dialyzer_codeserver:store_temp_contracts(Mod, SpecDict, CbDict, CS1);
		  {error, Reason} -> compile_error([Reason])
		end;
	      {error, Reason} -> compile_error([Reason])
	    end;
	  {error, Reason} -> compile_error(Reason)
	end
    end,
  CodeServer1 = lists:foldl(Fun, CodeServer, TrustedFiles),
  %% Process remote types
  NewCodeServer =
    try
      NewRecords = dialyzer_codeserver:get_temp_records(CodeServer1),
      NewExpTypes = dialyzer_codeserver:get_temp_exported_types(CodeServer1),
      case sets:size(NewExpTypes) of 0 -> ok end,
      OldRecords = dialyzer_plt:get_types(TrustPLT), % XXX change to the PLT?
      MergedRecords = dialyzer_utils:merge_records(NewRecords, OldRecords),
      CodeServer2 = dialyzer_codeserver:set_temp_records(MergedRecords, CodeServer1),
      CodeServer3 = dialyzer_codeserver:finalize_exported_types(NewExpTypes, CodeServer2),
      {CodeServer4, RecordDict} =
        dialyzer_utils:process_record_remote_types(CodeServer3),
      dialyzer_contracts:process_contract_remote_types(CodeServer4, RecordDict)
    catch
      throw:{error, ErrorMsg} ->
	compile_error(ErrorMsg)
    end,
  %% Create TrustPLT
  Contracts = dialyzer_codeserver:get_contracts(NewCodeServer),
  Modules = dict:fetch_keys(Contracts),
  FoldFun =
    fun(Module, TmpPlt) ->
	{ok, ModuleContracts} = dict:find(Module, Contracts),
	SpecList = [{MFA, Contract} 
		    || {MFA, {_FileLine, Contract}} <- maps:to_list(ModuleContracts)],
	dialyzer_plt:insert_contract_list(TmpPlt, SpecList)
    end,
  NewTrustPLT = lists:foldl(FoldFun, TrustPLT, Modules),
  Analysis#analysis{trust_plt = NewTrustPLT}.

%%--------------------------------------------------------------------

-spec get_type_info(analysis()) -> analysis().

get_type_info(#analysis{callgraph = CallGraph,
			trust_plt = TrustPLT,
			codeserver = CodeServer} = Analysis) ->
  StrippedCallGraph = remove_external(CallGraph, TrustPLT),
  %% io:format("--- Analyzing callgraph... "),
  try 
    NewMiniPlt = dialyzer_succ_typings:analyze_callgraph(StrippedCallGraph,
                                                         TrustPLT,
                                                         CodeServer),
    NewPlt = dialyzer_plt:restore_full_plt(NewMiniPlt),
    Analysis#analysis{callgraph = StrippedCallGraph, trust_plt = NewPlt}
  catch
    error:What ->
      fatal_error(io_lib:format("Analysis failed with message: ~p", 
				[{What, erlang:get_stacktrace()}]));
    throw:{dialyzer_succ_typing_error, Msg} ->
      fatal_error(io_lib:format("Analysis failed with message: ~s", [Msg]))
  end.

-spec remove_external(callgraph(), plt()) -> callgraph().

remove_external(CallGraph, PLT) ->
  {StrippedCG0, Ext} = dialyzer_callgraph:remove_external(CallGraph),
  case get_external(Ext, PLT) of
    [] -> ok;
    Externals ->
      msg(io_lib:format(" Unknown functions: ~p\n", [lists:usort(Externals)])),
      ExtTypes = rcv_ext_types(),
      case ExtTypes of
        [] -> ok;
        _ -> msg(io_lib:format(" Unknown types: ~p\n", [ExtTypes]))
      end
  end,
  StrippedCG0.

-spec get_external([{mfa(), mfa()}], plt()) -> [mfa()].

get_external(Exts, Plt) ->
  Fun = fun ({_From, To = {M, F, A}}, Acc) ->
	    case dialyzer_plt:contains_mfa(Plt, To) of
	      false ->
		case erl_bif_types:is_known(M, F, A) of
		  true -> Acc;
		  false -> [To|Acc]
		end;
	      true -> Acc
	    end
	end,
  lists:foldl(Fun, [], Exts).

%%--------------------------------------------------------------------
%% Showing type information or annotating files with such information.
%%--------------------------------------------------------------------

-define(TYPER_ANN_DIR, "typer_ann").

-type line()      :: non_neg_integer().
-type fa()        :: {atom(), arity()}.
-type func_info() :: {line(), atom(), arity()}.

-record(info, {records = maps:new() :: erl_types:type_table(),
	       functions = []       :: [func_info()],
	       types = map__new()   :: map_dict(),
	       edoc = false	    :: boolean()}).
-record(inc, {map = map__new() :: map_dict(), filter = [] :: files()}).
-type inc() :: #inc{}.

-spec show_or_annotate(analysis()) -> 'ok'.

show_or_annotate(#analysis{mode = Mode, fms = Files} = Analysis) ->
  case Mode of
    ?SHOW -> show(Analysis);
    ?SHOW_EXPORTED -> show(Analysis);
    ?ANNOTATE ->
      Fun = fun ({File, Module}) ->
		Info = get_final_info(File, Module, Analysis),
		write_typed_file(File, Info)
	    end,
      lists:foreach(Fun, Files);
    ?ANNOTATE_INC_FILES ->
      IncInfo = write_and_collect_inc_info(Analysis),
      write_inc_files(IncInfo)
  end.

write_and_collect_inc_info(Analysis) ->
  Fun = fun ({File, Module}, Inc) ->
	    Info = get_final_info(File, Module, Analysis),
	    write_typed_file(File, Info),
	    IncFuns = get_functions(File, Analysis),
	    collect_imported_functions(IncFuns, Info#info.types, Inc)
	end,
  NewInc = lists:foldl(Fun, #inc{}, Analysis#analysis.fms),
  clean_inc(NewInc).

write_inc_files(Inc) ->
  Fun =
    fun (File) ->
	Val = map__lookup(File, Inc#inc.map),
	%% Val is function with its type info
	%% in form [{{Line,F,A},Type}]
	Functions = [Key || {Key, _} <- Val],
	Val1 = [{{F,A},Type} || {{_Line,F,A},Type} <- Val],
	Info = #info{types = map__from_list(Val1),
		     records = maps:new(),
		     %% Note we need to sort functions here!
		     functions = lists:keysort(1, Functions)},
	%% io:format("Types ~p\n", [Info#info.types]),
	%% io:format("Functions ~p\n", [Info#info.functions]),
	%% io:format("Records ~p\n", [Info#info.records]),
	write_typed_file(File, Info)
    end,
  lists:foreach(Fun, dict:fetch_keys(Inc#inc.map)).

show(Analysis) ->
  Fun = fun ({File, Module}) ->
	    Info = get_final_info(File, Module, Analysis),
	    show_type_info(File, Info)
	end,
  lists:foreach(Fun, Analysis#analysis.fms).

get_final_info(File, Module, Analysis) ->
  Records = get_records(File, Analysis),
  Types = get_types(Module, Analysis, Records),
  Functions = get_functions(File, Analysis),
  Edoc = Analysis#analysis.edoc,
  #info{records = Records, functions = Functions, types = Types, edoc = Edoc}.

collect_imported_functions(Functions, Types, Inc) ->
  %% Coming from other sourses, including:
  %% FIXME: How to deal with yecc-generated file????
  %%     --.yrl (yecc-generated file)???
  %%     -- yeccpre.hrl (yecc-generated file)???
  %%     -- other cases
  Fun = fun ({File, _} = Obj, I) ->
	    case is_yecc_gen(File, I) of
	      {true, NewI} -> NewI;
	      {false, NewI} ->
		check_imported_functions(Obj, NewI, Types)
	    end
	end,
  lists:foldl(Fun, Inc, Functions).

-spec is_yecc_gen(file:filename(), inc()) -> {boolean(), inc()}.

is_yecc_gen(File, #inc{filter = Fs} = Inc) ->
  case lists:member(File, Fs) of
    true -> {true, Inc};
    false ->
      case filename:extension(File) of
	".yrl" ->
	  Rootname = filename:rootname(File, ".yrl"),
	  Obj = Rootname ++ ".erl",
	  case lists:member(Obj, Fs) of
	    true -> {true, Inc};
	    false ->
	      NewInc = Inc#inc{filter = [Obj|Fs]},
	      {true, NewInc}
	  end;
	_ ->
	  case filename:basename(File) of
	    "yeccpre.hrl" -> {true, Inc};
	    _ -> {false, Inc}
	  end
      end
  end.

check_imported_functions({File, {Line, F, A}}, Inc, Types) ->
  IncMap = Inc#inc.map,
  FA = {F, A},
  Type = get_type_info(FA, Types),
  case map__lookup(File, IncMap) of
    none -> %% File is not added. Add it
      Obj = {File,[{FA, {Line, Type}}]},
      NewMap = map__insert(Obj, IncMap),
      Inc#inc{map = NewMap};
    Val -> %% File is already in. Check.
      case lists:keyfind(FA, 1, Val) of
	false ->
	  %% Function is not in; add it
	  Obj = {File, Val ++ [{FA, {Line, Type}}]},
	  NewMap = map__insert(Obj, IncMap),
	  Inc#inc{map = NewMap};
	Type ->
	  %% Function is in and with same type
	  Inc;
	_ ->
	  %% Function is in but with diff type
	  inc_warning(FA, File),
	  Elem = lists:keydelete(FA, 1, Val),
	  NewMap = case Elem of
		     [] -> map__remove(File, IncMap);
		     _  -> map__insert({File, Elem}, IncMap)
		   end,
	  Inc#inc{map = NewMap}
      end
  end.

inc_warning({F, A}, File) ->
  io:format("      ***Warning: Skip function ~p/~p ", [F, A]),
  io:format("in file ~p because of inconsistent type\n", [File]).

clean_inc(Inc) ->
  Inc1 = remove_yecc_generated_file(Inc),
  normalize_obj(Inc1).

remove_yecc_generated_file(#inc{filter = Filter} = Inc) ->
  Fun = fun (Key, #inc{map = Map} = I) ->
	    I#inc{map = map__remove(Key, Map)}
	end,
  lists:foldl(Fun, Inc, Filter).

normalize_obj(TmpInc) ->
  Fun = fun (Key, Val, Inc) ->
	    NewVal = [{{Line,F,A},Type} || {{F,A},{Line,Type}} <- Val],
	    map__insert({Key, NewVal}, Inc)
	end,
  TmpInc#inc{map = map__fold(Fun, map__new(), TmpInc#inc.map)}.

get_records(File, Analysis) ->
  map__lookup(File, Analysis#analysis.record).

get_types(Module, Analysis, Records) ->
  TypeInfoPlt = Analysis#analysis.trust_plt,
  TypeInfo = 
    case dialyzer_plt:lookup_module(TypeInfoPlt, Module) of
      none -> [];
      {value, List} -> List
    end,
  CodeServer = Analysis#analysis.codeserver,
  TypeInfoList =
    case Analysis#analysis.show_succ of
      true ->
	[convert_type_info(I) || I <- TypeInfo];
      false ->
	[get_type(I, CodeServer, Records) || I <- TypeInfo]
    end,
  map__from_list(TypeInfoList).

convert_type_info({{_M, F, A}, Range, Arg}) ->
  {{F, A}, {Range, Arg}}.

get_type({{M, F, A} = MFA, Range, Arg}, CodeServer, Records) ->
  case dialyzer_codeserver:lookup_mfa_contract(MFA, CodeServer) of
    error ->
      {{F, A}, {Range, Arg}};
    {ok, {_FileLine, Contract, _Xtra}} ->
      Sig = erl_types:t_fun(Arg, Range),
      case dialyzer_contracts:check_contract(Contract, Sig) of
	ok -> {{F, A}, {contract, Contract}};
	{error, {extra_range, _, _}} ->
	  {{F, A}, {contract, Contract}};
	{error, {overlapping_contract, []}} ->
	  {{F, A}, {contract, Contract}};
	{error, invalid_contract} ->
	  CString = dialyzer_contracts:contract_to_string(Contract),
	  SigString = dialyzer_utils:format_sig(Sig, Records),
	  Msg = io_lib:format("Error in contract of function ~w:~w/~w\n" 
			      "\t The contract is: " ++ CString ++ "\n" ++
			      "\t but the inferred signature is: ~s",
			      [M, F, A, SigString]),
	  fatal_error(Msg);
	{error, ErrorStr} when is_list(ErrorStr) -> % ErrorStr is a string()
	  Msg = io_lib:format("Error in contract of function ~w:~w/~w: ~s",
			      [M, F, A, ErrorStr]),
	  fatal_error(Msg)
      end
  end.

get_functions(File, Analysis) ->
  case Analysis#analysis.mode of
    ?SHOW ->
      Funcs = map__lookup(File, Analysis#analysis.func),
      Inc_Funcs = map__lookup(File, Analysis#analysis.inc_func),
      remove_module_info(Funcs) ++ normalize_incFuncs(Inc_Funcs);
    ?SHOW_EXPORTED ->
      Ex_Funcs = map__lookup(File, Analysis#analysis.ex_func),
      remove_module_info(Ex_Funcs);
    ?ANNOTATE ->
      Funcs = map__lookup(File, Analysis#analysis.func),
      remove_module_info(Funcs);
    ?ANNOTATE_INC_FILES ->
      map__lookup(File, Analysis#analysis.inc_func)
  end.

normalize_incFuncs(Functions) ->
  [FunInfo || {_FileName, FunInfo} <- Functions].

-spec remove_module_info([func_info()]) -> [func_info()].

remove_module_info(FunInfoList) ->
  F = fun ({_,module_info,0}) -> false;
	  ({_,module_info,1}) -> false;
	  ({Line,F,A}) when is_integer(Line), is_atom(F), is_integer(A) -> true
      end,
  lists:filter(F, FunInfoList).

write_typed_file(File, Info) ->
  io:format("      Processing file: ~p\n", [File]),
  Dir = filename:dirname(File),
  RootName = filename:basename(filename:rootname(File)),
  Ext = filename:extension(File),
  TyperAnnDir = filename:join(Dir, ?TYPER_ANN_DIR),
  TmpNewFilename = lists:concat([RootName, ".ann", Ext]),
  NewFileName = filename:join(TyperAnnDir, TmpNewFilename),
  case file:make_dir(TyperAnnDir) of
    {error, Reason} ->
      case Reason of
	eexist -> %% TypEr dir exists; remove old typer files if they exist
	  case file:delete(NewFileName) of
	    ok -> ok;
	    {error, enoent} -> ok;
	    {error, _} ->
	      Msg = io_lib:format("Error in deleting file ~s\n", [NewFileName]),
	      fatal_error(Msg)
	  end,
	  write_typed_file(File, Info, NewFileName);
	enospc ->
	  Msg = io_lib:format("Not enough space in ~p\n", [Dir]),
	  fatal_error(Msg);
	eacces ->
	  Msg = io_lib:format("No write permission in ~p\n", [Dir]),
	  fatal_error(Msg);
	_ ->
	  Msg = io_lib:format("Unhandled error ~s when writing ~p\n",
			      [Reason, Dir]),
	  fatal_error(Msg)
      end;
    ok -> %% Typer dir does NOT exist
      write_typed_file(File, Info, NewFileName)
  end.

write_typed_file(File, Info, NewFileName) ->
  {ok, Binary} = file:read_file(File),
  Chars = binary_to_list(Binary),
  write_typed_file(Chars, NewFileName, Info, 1, []),
  io:format("             Saved as: ~p\n", [NewFileName]).

write_typed_file(Chars, File, #info{functions = []}, _LNo, _Acc) ->
  ok = file:write_file(File, list_to_binary(Chars), [append]);
write_typed_file([Ch|Chs] = Chars, File, Info, LineNo, Acc) ->
  [{Line,F,A}|RestFuncs] = Info#info.functions,
  case Line of
    1 -> %% This will happen only for inc files
      ok = raw_write(F, A, Info, File, []),
      NewInfo = Info#info{functions = RestFuncs},
      NewAcc = [],
      write_typed_file(Chars, File, NewInfo, Line, NewAcc);
    _ ->
      case Ch of
	10 ->
	  NewLineNo = LineNo + 1,
	  {NewInfo, NewAcc} =
	    case NewLineNo of
	      Line ->
		ok = raw_write(F, A, Info, File, [Ch|Acc]),
		{Info#info{functions = RestFuncs}, []};
	      _ ->
		{Info, [Ch|Acc]}
	    end,
	  write_typed_file(Chs, File, NewInfo, NewLineNo, NewAcc);
	_ ->
	  write_typed_file(Chs, File, Info, LineNo, [Ch|Acc])
      end
  end.

raw_write(F, A, Info, File, Content) ->
  TypeInfo = get_type_string(F, A, Info, file),
  ContentList = lists:reverse(Content) ++ TypeInfo ++ "\n",
  ContentBin = list_to_binary(ContentList),
  file:write_file(File, ContentBin, [append]).

get_type_string(F, A, Info, Mode) ->
  Type = get_type_info({F,A}, Info#info.types),
  TypeStr =
    case Type of
      {contract, C} -> 
        dialyzer_contracts:contract_to_string(C);
      {RetType, ArgType} ->
	Sig = erl_types:t_fun(ArgType, RetType),
        dialyzer_utils:format_sig(Sig, Info#info.records)
    end,
  case Info#info.edoc of
    false ->
      case {Mode, Type} of
	{file, {contract, _}} -> "";
	_ ->
	  Prefix = lists:concat(["-spec ", erl_types:atom_to_string(F)]),
	  lists:concat([Prefix, TypeStr, "."])
      end;
    true ->
      Prefix = lists:concat(["%% @spec ", F]),
      lists:concat([Prefix, TypeStr, "."])
  end.
 
show_type_info(File, Info) ->
  io:format("\n%% File: ~p\n%% ", [File]),
  OutputString = lists:concat(["~.", length(File)+8, "c~n"]),
  io:fwrite(OutputString, [$-]),
  Fun = fun ({_LineNo, F, A}) ->
	    TypeInfo = get_type_string(F, A, Info, show),
	    io:format("~s\n", [TypeInfo])
	end,
  lists:foreach(Fun, Info#info.functions).

get_type_info(Func, Types) ->
  case map__lookup(Func, Types) of
    none ->
      %% Note: Typeinfo of any function should exist in
      %% the result offered by dialyzer, otherwise there 
      %% *must* be something wrong with the analysis
      Msg = io_lib:format("No type info for function: ~p\n", [Func]),
      fatal_error(Msg);
    {contract, _Fun} = C -> C;
    {_RetType, _ArgType} = RA -> RA 
  end.

%%--------------------------------------------------------------------
%% Processing of command-line options and arguments.
%%--------------------------------------------------------------------

-spec process_cl_args() -> {args(), analysis()}.

process_cl_args() ->
  ArgList = init:get_plain_arguments(),
  %% io:format("Args is ~p\n", [ArgList]),
  {Args, Analysis} = analyze_args(ArgList, #args{}, #analysis{}),
  %% if the mode has not been set, set it to the default mode (show)
  {Args, case Analysis#analysis.mode of
	   undefined -> Analysis#analysis{mode = ?SHOW};
	   Mode when is_atom(Mode) -> Analysis
	 end}.

analyze_args([], Args, Analysis) ->
  {Args, Analysis};
analyze_args(ArgList, Args, Analysis) ->
  {Result, Rest} = cl(ArgList),
  {NewArgs, NewAnalysis} = analyze_result(Result, Args, Analysis),
  analyze_args(Rest, NewArgs, NewAnalysis).

cl(["-h"|_])     -> help_message();
cl(["--help"|_]) -> help_message();
cl(["-v"|_])        -> version_message();
cl(["--version"|_]) -> version_message();
cl(["--edoc"|Opts]) -> {edoc, Opts};
cl(["--show"|Opts]) -> {{mode, ?SHOW}, Opts};
cl(["--show_exported"|Opts]) -> {{mode, ?SHOW_EXPORTED}, Opts};
cl(["--show-exported"|Opts]) -> {{mode, ?SHOW_EXPORTED}, Opts};
cl(["--show_success_typings"|Opts]) -> {show_succ, Opts};
cl(["--show-success-typings"|Opts]) -> {show_succ, Opts};
cl(["--annotate"|Opts]) -> {{mode, ?ANNOTATE}, Opts};
cl(["--annotate-inc-files"|Opts]) -> {{mode, ?ANNOTATE_INC_FILES}, Opts};
cl(["--no_spec"|Opts]) -> {no_spec, Opts};
cl(["--plt",Plt|Opts]) -> {{plt, Plt}, Opts};
cl(["-D"++Def|Opts]) ->
  case Def of
    "" -> fatal_error("no variable name specified after -D");
    _ ->
      DefPair = process_def_list(re:split(Def, "=", [{return, list}])),
      {{def, DefPair}, Opts}
  end;
cl(["-I",Dir|Opts]) -> {{inc, Dir}, Opts};
cl(["-I"++Dir|Opts]) ->
  case Dir of
    "" -> fatal_error("no include directory specified after -I");
    _ -> {{inc, Dir}, Opts}
  end;
cl(["-T"|Opts]) ->
  {Files, RestOpts} = dialyzer_cl_parse:collect_args(Opts),
  case Files of
    [] -> fatal_error("no file or directory specified after -T");
    [_|_] -> {{trusted, Files}, RestOpts}
  end;
cl(["-r"|Opts]) ->
  {Files, RestOpts} = dialyzer_cl_parse:collect_args(Opts),
  {{files_r, Files}, RestOpts};
cl(["-pa",Dir|Opts]) -> {{pa,Dir}, Opts};
cl(["-pz",Dir|Opts]) -> {{pz,Dir}, Opts};
cl(["-"++H|_]) -> fatal_error("unknown option -"++H);
cl(Opts) -> 
  {Files, RestOpts} = dialyzer_cl_parse:collect_args(Opts),
  {{files, Files}, RestOpts}.

process_def_list(L) ->
  case L of
    [Name, Value] ->
      {ok, Tokens, _} = erl_scan:string(Value ++ "."),
      {ok, ErlValue} = erl_parse:parse_term(Tokens),
      {list_to_atom(Name), ErlValue};
    [Name] ->
      {list_to_atom(Name), true}
  end.

%% Get information about files that the user trusts and wants to analyze
analyze_result({files, Val}, Args, Analysis) ->
  NewVal = Args#args.files ++ Val,
  {Args#args{files = NewVal}, Analysis};
analyze_result({files_r, Val}, Args, Analysis) ->
  NewVal = Args#args.files_r ++ Val,
  {Args#args{files_r = NewVal}, Analysis};
analyze_result({trusted, Val}, Args, Analysis) ->
  NewVal = Args#args.trusted ++ Val,
  {Args#args{trusted = NewVal}, Analysis};
analyze_result(edoc, Args, Analysis) ->
  {Args, Analysis#analysis{edoc = true}};
%% Get useful information for actual analysis
analyze_result({mode, Mode}, Args, Analysis) ->
  case Analysis#analysis.mode of
    undefined -> {Args, Analysis#analysis{mode = Mode}};
    OldMode -> mode_error(OldMode, Mode)
  end;
analyze_result({def, Val}, Args, Analysis) ->
  NewVal = Analysis#analysis.macros ++ [Val],
  {Args, Analysis#analysis{macros = NewVal}};
analyze_result({inc, Val}, Args, Analysis) ->
  NewVal = Analysis#analysis.includes ++ [Val],
  {Args, Analysis#analysis{includes = NewVal}};
analyze_result({plt, Plt}, Args, Analysis) ->
  {Args, Analysis#analysis{plt = Plt}};
analyze_result(show_succ, Args, Analysis) ->
  {Args, Analysis#analysis{show_succ = true}};
analyze_result(no_spec, Args, Analysis) ->
  {Args, Analysis#analysis{no_spec = true}};
analyze_result({pa, Dir}, Args, Analysis) ->
  true = code:add_patha(Dir),
  {Args, Analysis};
analyze_result({pz, Dir}, Args, Analysis) ->
  true = code:add_pathz(Dir),
  {Args, Analysis}.

%%--------------------------------------------------------------------
%% File processing.
%%--------------------------------------------------------------------

-spec get_all_files(args()) -> [file:filename(),...].

get_all_files(#args{files = Fs, files_r = Ds}) ->
  case filter_fd(Fs, Ds, fun test_erl_file_exclude_ann/1) of
    [] -> fatal_error("no file(s) to analyze");
    AllFiles -> AllFiles
  end.

-spec test_erl_file_exclude_ann(file:filename()) -> boolean().

test_erl_file_exclude_ann(File) ->
  case is_erl_file(File) of
    true -> %% Exclude files ending with ".ann.erl"
      case re:run(File, "[\.]ann[\.]erl$") of
	{match, _} -> false;
	nomatch -> true
      end;
    false -> false
  end.

-spec is_erl_file(file:filename()) -> boolean().

is_erl_file(File) ->
  filename:extension(File) =:= ".erl".

-type test_file_fun() :: fun((file:filename()) -> boolean()).

-spec filter_fd(files(), files(), test_file_fun()) -> files().

filter_fd(File_Dir, Dir_R, Fun) ->
  All_File_1 = process_file_and_dir(File_Dir, Fun),
  All_File_2 = process_dir_rec(Dir_R, Fun),
  remove_dup(All_File_1 ++ All_File_2).

-spec process_file_and_dir(files(), test_file_fun()) -> files().

process_file_and_dir(File_Dir, TestFun) ->
  Fun =
    fun (Elem, Acc) ->
	case filelib:is_regular(Elem) of
	  true  -> process_file(Elem, TestFun, Acc);
	  false -> check_dir(Elem, false, Acc, TestFun)
	end
    end,
  lists:foldl(Fun, [], File_Dir).

-spec process_dir_rec(files(), test_file_fun()) -> files().

process_dir_rec(Dirs, TestFun) ->
  Fun = fun (Dir, Acc) -> check_dir(Dir, true, Acc, TestFun) end,
  lists:foldl(Fun, [], Dirs).

-spec check_dir(file:filename(), boolean(), files(), test_file_fun()) -> files().

check_dir(Dir, Recursive, Acc, Fun) ->
  case file:list_dir(Dir) of
    {ok, Files} ->
      {TmpDirs, TmpFiles} = split_dirs_and_files(Files, Dir),
      case Recursive of
	false ->
	  FinalFiles = process_file_and_dir(TmpFiles, Fun),
	  Acc ++ FinalFiles;
	true ->
	  TmpAcc1 = process_file_and_dir(TmpFiles, Fun),
	  TmpAcc2 = process_dir_rec(TmpDirs, Fun),
	  Acc ++ TmpAcc1 ++ TmpAcc2
      end;
    {error, eacces} ->
      fatal_error("no access permission to dir \""++Dir++"\"");
    {error, enoent} ->
      fatal_error("cannot access "++Dir++": No such file or directory");
    {error, _Reason} ->
      fatal_error("error involving a use of file:list_dir/1")
  end.

%% Same order as the input list
-spec process_file(file:filename(), test_file_fun(), files()) -> files().

process_file(File, TestFun, Acc) ->
  case TestFun(File) of
    true  -> Acc ++ [File];
    false -> Acc
  end.

%% Same order as the input list
-spec split_dirs_and_files(files(), file:filename()) -> {files(), files()}.

split_dirs_and_files(Elems, Dir) ->
  Test_Fun =
    fun (Elem, {DirAcc, FileAcc}) ->
	File = filename:join(Dir, Elem),
	case filelib:is_regular(File) of
	  false -> {[File|DirAcc], FileAcc}; 
	  true  -> {DirAcc, [File|FileAcc]}
	end
    end,
  {Dirs, Files} = lists:foldl(Test_Fun, {[], []}, Elems),
  {lists:reverse(Dirs), lists:reverse(Files)}.  

%% Removes duplicate filenames but keeps the order of the input list
-spec remove_dup(files()) -> files().

remove_dup(Files) ->
  Test_Dup = fun (File, Acc) ->
		 case lists:member(File, Acc) of
		   true  -> Acc;
		   false -> [File|Acc]
		 end
	     end,
  Reversed_Elems = lists:foldl(Test_Dup, [], Files),
  lists:reverse(Reversed_Elems).

%%--------------------------------------------------------------------
%% Collect information.
%%--------------------------------------------------------------------

-type inc_file_info() :: {file:filename(), func_info()}.

-record(tmpAcc, {file		  :: file:filename(),
		 module		  :: atom(),
		 funcAcc = []	  :: [func_info()],
		 incFuncAcc = []  :: [inc_file_info()],
		 dialyzerObj = [] :: [{mfa(), {_, _}}]}).

-spec collect_info(analysis()) -> analysis().

collect_info(Analysis) ->
  NewPlt =
    try get_dialyzer_plt(Analysis) of
	DialyzerPlt ->
	dialyzer_plt:merge_plts([Analysis#analysis.trust_plt, DialyzerPlt])
    catch
      throw:{dialyzer_error,_Reason} ->
	fatal_error("Dialyzer's PLT is missing or is not up-to-date; please (re)create it")
    end,
  NewAnalysis = lists:foldl(fun collect_one_file_info/2, 
			    Analysis#analysis{trust_plt = NewPlt}, 
			    Analysis#analysis.files),
  %% Process Remote Types
  TmpCServer = NewAnalysis#analysis.codeserver,
  NewCServer =
    try
      NewRecords = dialyzer_codeserver:get_temp_records(TmpCServer),
      NewExpTypes = dialyzer_codeserver:get_temp_exported_types(TmpCServer),
      OldRecords = dialyzer_plt:get_types(NewPlt),
      OldExpTypes = dialyzer_plt:get_exported_types(NewPlt),
      MergedRecords = dialyzer_utils:merge_records(NewRecords, OldRecords),
      MergedExpTypes = sets:union(NewExpTypes, OldExpTypes),
      %% io:format("Merged Records ~p",[MergedRecords]),
      TmpCServer1 = dialyzer_codeserver:set_temp_records(MergedRecords, TmpCServer),
      TmpCServer2 =
        dialyzer_codeserver:finalize_exported_types(MergedExpTypes, TmpCServer1),
      {TmpCServer3, RecordDict} =
        dialyzer_utils:process_record_remote_types(TmpCServer2),
      dialyzer_contracts:process_contract_remote_types(TmpCServer3, RecordDict)
    catch
      throw:{error, ErrorMsg} ->
	fatal_error(ErrorMsg)
    end,
  NewAnalysis#analysis{codeserver = NewCServer}.

collect_one_file_info(File, Analysis) ->
  Ds = [{d,Name,Val} || {Name,Val} <- Analysis#analysis.macros],
  %% Current directory should also be included in "Includes".
  Includes = [filename:dirname(File)|Analysis#analysis.includes],
  Is = [{i,Dir} || Dir <- Includes],
  Options = dialyzer_utils:src_compiler_opts() ++ Is ++ Ds,
  case dialyzer_utils:get_abstract_code_from_src(File, Options) of
    {error, Reason} ->
      %% io:format("File=~p\n,Options=~p\n,Error=~p\n", [File,Options,Reason]),
      compile_error(Reason);
    {ok, AbstractCode} ->
      case dialyzer_utils:get_core_from_abstract_code(AbstractCode, Options) of
	error -> compile_error(["Could not get core erlang for "++File]);
	{ok, Core} ->
	  case dialyzer_utils:get_record_and_type_info(AbstractCode) of
	    {error, Reason} -> compile_error([Reason]);
	    {ok, Records} ->
	      Mod = cerl:concrete(cerl:module_name(Core)),
	      case dialyzer_utils:get_spec_info(Mod, AbstractCode, Records) of
		{error, Reason} -> compile_error([Reason]);
		{ok, SpecInfo, CbInfo} ->
                  ExpTypes = get_exported_types_from_core(Core),
		  analyze_core_tree(Core, Records, SpecInfo, CbInfo,
				    ExpTypes, Analysis, File)
	      end
	  end
      end
  end.

analyze_core_tree(Core, Records, SpecInfo, CbInfo, ExpTypes, Analysis, File) ->
  Module = cerl:concrete(cerl:module_name(Core)),
  TmpTree = cerl:from_records(Core),
  CS1 = Analysis#analysis.codeserver,
  NextLabel = dialyzer_codeserver:get_next_core_label(CS1),
  {Tree, NewLabel} = cerl_trees:label(TmpTree, NextLabel),
  CS2 = dialyzer_codeserver:insert(Module, Tree, CS1),
  CS3 = dialyzer_codeserver:set_next_core_label(NewLabel, CS2),
  CS4 = dialyzer_codeserver:store_temp_records(Module, Records, CS3),
  CS5 =
    case Analysis#analysis.no_spec of
      true -> CS4;
      false ->
	dialyzer_codeserver:store_temp_contracts(Module, SpecInfo, CbInfo, CS4)
    end,
  OldExpTypes = dialyzer_codeserver:get_temp_exported_types(CS5),
  MergedExpTypes = sets:union(ExpTypes, OldExpTypes),
  CS6 = dialyzer_codeserver:insert_temp_exported_types(MergedExpTypes, CS5),
  Ex_Funcs = [{0,F,A} || {_,_,{F,A}} <- cerl:module_exports(Tree)],
  CG = Analysis#analysis.callgraph,
  {V, E} = dialyzer_callgraph:scan_core_tree(Tree, CG),
  dialyzer_callgraph:add_edges(E, V, CG),
  Fun = fun analyze_one_function/2,
  All_Defs = cerl:module_defs(Tree),
  Acc = lists:foldl(Fun, #tmpAcc{file = File, module = Module}, All_Defs),
  Exported_FuncMap = map__insert({File, Ex_Funcs}, Analysis#analysis.ex_func),
  %% we must sort all functions in the file which
  %% originate from this file by *numerical order* of lineNo
  Sorted_Functions = lists:keysort(1, Acc#tmpAcc.funcAcc),
  FuncMap = map__insert({File, Sorted_Functions}, Analysis#analysis.func),
  %% we do not need to sort functions which are imported from included files
  IncFuncMap = map__insert({File, Acc#tmpAcc.incFuncAcc},
			   Analysis#analysis.inc_func),
  FMs = Analysis#analysis.fms ++ [{File, Module}],
  RecordMap = map__insert({File, Records}, Analysis#analysis.record),
  Analysis#analysis{fms = FMs,
		    callgraph = CG,
		    codeserver = CS6,
		    ex_func = Exported_FuncMap,
		    inc_func = IncFuncMap,
		    record = RecordMap,
		    func = FuncMap}.

analyze_one_function({Var, FunBody} = Function, Acc) ->
  F = cerl:fname_id(Var),
  A = cerl:fname_arity(Var),
  TmpDialyzerObj = {{Acc#tmpAcc.module, F, A}, Function},
  NewDialyzerObj = Acc#tmpAcc.dialyzerObj ++ [TmpDialyzerObj],  
  Anno = cerl:get_ann(FunBody),
  LineNo = get_line(Anno),
  FileName = get_file(Anno),
  BaseName = filename:basename(FileName),
  FuncInfo = {LineNo, F, A},
  OriginalName = Acc#tmpAcc.file,
  {FuncAcc, IncFuncAcc} =
    case (FileName =:= OriginalName) orelse (BaseName =:= OriginalName) of
      true -> %% Coming from original file
	%% io:format("Added function ~p\n", [{LineNo, F, A}]),
	{Acc#tmpAcc.funcAcc ++ [FuncInfo], Acc#tmpAcc.incFuncAcc};
      false ->
	%% Coming from other sourses, including:
	%%     -- .yrl (yecc-generated file)
	%%     -- yeccpre.hrl (yecc-generated file)
	%%     -- other cases
	{Acc#tmpAcc.funcAcc, Acc#tmpAcc.incFuncAcc ++ [{FileName, FuncInfo}]}
    end,
  Acc#tmpAcc{funcAcc = FuncAcc,
	     incFuncAcc = IncFuncAcc,
	     dialyzerObj = NewDialyzerObj}.

get_line([Line|_]) when is_integer(Line) -> Line;
get_line([_|T]) -> get_line(T);
get_line([]) -> none.

get_file([{file,File}|_]) -> File;
get_file([_|T]) -> get_file(T);
get_file([]) -> "no_file". % should not happen

-spec get_dialyzer_plt(analysis()) -> plt().

get_dialyzer_plt(#analysis{plt = PltFile0}) ->
  PltFile =
    case PltFile0 =:= none of
      true -> dialyzer_plt:get_default_plt();
      false -> PltFile0
    end,
  dialyzer_plt:from_file(PltFile).

%% Exported Types

get_exported_types_from_core(Core) ->
  Attrs = cerl:module_attrs(Core),
  ExpTypes1 = [cerl:concrete(L2) || {L1, L2} <- Attrs,
                                    cerl:is_literal(L1),
                                    cerl:is_literal(L2),
                                    cerl:concrete(L1) =:= 'export_type'],
  ExpTypes2 = lists:flatten(ExpTypes1),
  M = cerl:atom_val(cerl:module_name(Core)),
  sets:from_list([{M, F, A} || {F, A} <- ExpTypes2]).

%%--------------------------------------------------------------------
%% Utilities for error reporting.
%%--------------------------------------------------------------------

-spec fatal_error(string()) -> no_return().

fatal_error(Slogan) ->
  msg(io_lib:format("typer: ~s\n", [Slogan])),
  erlang:halt(1).

-spec mode_error(mode(), mode()) -> no_return().

mode_error(OldMode, NewMode) ->
  Msg = io_lib:format("Mode was previously set to '~s'; "
		      "can not set it to '~s' now",
		      [OldMode, NewMode]),
  fatal_error(Msg).

-spec compile_error([string()]) -> no_return().

compile_error(Reason) ->
  JoinedString = lists:flatten([X ++ "\n" || X <- Reason]),
  Msg = "Analysis failed with error report:\n" ++ JoinedString,
  fatal_error(Msg).

-spec msg(string()) -> 'ok'.

msg(Msg) ->
  io:format(standard_error, "~s", [Msg]).

%%--------------------------------------------------------------------
%% Version and help messages.
%%--------------------------------------------------------------------

-spec version_message() -> no_return().

version_message() ->
  io:format("TypEr version "++?VSN++"\n"),
  erlang:halt(0).

-spec help_message() -> no_return().

help_message() ->
  S = <<" Usage: typer [--help] [--version] [--plt PLT] [--edoc]
              [--show | --show-exported | --annotate | --annotate-inc-files]
              [-Ddefine]* [-I include_dir]* [-pa dir]* [-pz dir]*
              [-T application]* [-r] file*

 Options:
   -r dir*
       search directories recursively for .erl files below them
   --show
       Prints type specifications for all functions on stdout.
       (this is the default behaviour; this option is not really needed)
   --show-exported (or --show_exported)
       Same as --show, but prints specifications for exported functions only
       Specs are displayed sorted alphabetically on the function's name
   --annotate
       Annotates the specified files with type specifications
   --annotate-inc-files
       Same as --annotate but annotates all -include() files as well as
       all .erl files (use this option with caution - has not been tested much)
   --edoc
       Prints type information as Edoc @spec comments, not as type specs
   --plt PLT
       Use the specified dialyzer PLT file rather than the default one
   -T file*
       The specified file(s) already contain type specifications and these
       are to be trusted in order to print specs for the rest of the files
       (Multiple files or dirs, separated by spaces, can be specified.)
   -Dname (or -Dname=value)
       pass the defined name(s) to TypEr
       (The syntax of defines is the same as that used by \"erlc\".)
   -I include_dir
       pass the include_dir to TypEr
       (The syntax of includes is the same as that used by \"erlc\".)
   -pa dir
   -pz dir
       Set code path options to TypEr
       (This is useful for files that use parse tranforms.)
   --version (or -v)
       prints the Typer version and exits
   --help (or -h)
       prints this message and exits

 Note:
   * denotes that multiple occurrences of these options are possible.
">>,
  io:put_chars(S),
  erlang:halt(0).

%%--------------------------------------------------------------------
%% Handle messages.                         
%%-------------------------------------------------------------------- 

rcv_ext_types() ->
  Self = self(),
  Self ! {Self, done},
  rcv_ext_types(Self, []).

rcv_ext_types(Self, ExtTypes) ->
  receive
    {Self, ext_types, ExtType} ->
      rcv_ext_types(Self, [ExtType|ExtTypes]);
    {Self, done} ->
      lists:usort(ExtTypes)
  end.

%%--------------------------------------------------------------------
%% A convenient abstraction of a Key-Value mapping data structure
%% specialized for the uses in this module
%%--------------------------------------------------------------------

-type map_dict() :: dict:dict().

-spec map__new() -> map_dict().
map__new() ->
  dict:new().

-spec map__insert({term(), term()}, map_dict()) -> map_dict().
map__insert(Object, Map) ->
  {Key, Value} = Object,
  dict:store(Key, Value, Map).

-spec map__lookup(term(), map_dict()) -> term().
map__lookup(Key, Map) ->
  try dict:fetch(Key, Map) catch error:_ -> none end.

-spec map__from_list([{fa(), term()}]) -> map_dict().
map__from_list(List) ->
  dict:from_list(List).

-spec map__remove(term(), map_dict()) -> map_dict().
map__remove(Key, Dict) ->
  dict:erase(Key, Dict).

-spec map__fold(fun((term(), term(), term()) -> map_dict()), map_dict(), map_dict()) -> map_dict().
map__fold(Fun, Acc0, Dict) -> 
  dict:fold(Fun, Acc0, Dict).