mirrored from https://gitlab.haskell.org/ghc/ghc.git
-
Notifications
You must be signed in to change notification settings - Fork 705
/
flags.xml
3315 lines (3121 loc) · 127 KB
/
flags.xml
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
<?xml version="1.0" encoding="iso-8859-1"?>
<sect1 id="flag-reference">
<title>Flag reference</title>
<para>This section is a quick-reference for GHC's command-line
flags. For each flag, we also list its static/dynamic status (see
<xref linkend="static-dynamic-flags"/>), and the flag's opposite
(if available).</para>
<sect2>
<title>Verbosity options</title>
<para>More details in <xref linkend="options-help"/></para>
<informaltable>
<tgroup cols="4" align="left" colsep="1" rowsep="1">
<thead>
<row>
<entry>Flag</entry>
<entry>Description</entry>
<entry>Static/Dynamic</entry>
<entry>Reverse</entry>
</row>
</thead>
<tbody>
<row>
<entry><option>-v</option></entry>
<entry>verbose mode (equivalent to <option>-v3</option>)</entry>
<entry>dynamic</entry>
<entry>-</entry>
</row>
<row>
<entry><option>-v</option><replaceable>n</replaceable></entry>
<entry>set verbosity level</entry>
<entry>dynamic</entry>
<entry>-</entry>
</row>
<row>
<entry><option>-fprint-explicit-foralls</option></entry>
<entry>print explicit <literal>forall</literal> quantification in types</entry>
<entry>dynamic</entry>
<entry>-fno-print-explicit-foralls</entry>
</row>
<row>
<entry><option>-fprint-explicit-kinds</option></entry>
<entry>print explicit kind foralls and kind arguments in types</entry>
<entry>dynamic</entry>
<entry>-fno-print-explicit-kinds</entry>
</row>
<row>
<entry><option>-ferror-spans</option></entry>
<entry>output full span in error messages</entry>
<entry>dynamic</entry>
<entry>-</entry>
</row>
<row>
<entry><option>-H</option><replaceable>size</replaceable></entry>
<entry>Set the minimum heap size to <replaceable>size</replaceable></entry>
<entry>dynamic</entry>
<entry>-</entry>
</row>
<row>
<entry><option>-Rghc-timing</option></entry>
<entry>Summarise timing stats for GHC (same as <literal>+RTS -tstderr</literal>)</entry>
<entry>dynamic</entry>
<entry>-</entry>
</row>
</tbody>
</tgroup>
</informaltable>
</sect2>
<sect2>
<title>Alternative modes of operation</title>
<para>More details in <xref linkend="modes"/></para>
<informaltable>
<tgroup cols="4" align="left" colsep="1" rowsep="1">
<thead>
<row>
<entry>Flag</entry>
<entry>Description</entry>
<entry>Static/Dynamic</entry>
<entry>Reverse</entry>
</row>
</thead>
<tbody>
<row>
<entry><option>--help</option>,<option>-?</option></entry>
<entry>Disply help</entry>
<entry>mode</entry>
<entry>-</entry>
</row>
<row>
<entry><option>--interactive</option></entry>
<entry>Interactive mode - normally used by just running <command>ghci</command>;
see <xref linkend="ghci"/> for details.</entry>
<entry>mode</entry>
<entry>-</entry>
</row>
<row>
<entry><option>--make</option></entry>
<entry>Build a multi-module Haskell program, automatically figuring out dependencies. Likely to be much easier, and faster, than using <command>make</command>;
see <xref linkend="make-mode"/> for details..</entry>
<entry>mode</entry>
<entry>-</entry>
</row>
<row>
<entry><option>-e <replaceable>expr</replaceable></option></entry>
<entry>Evaluate <replaceable>expr</replaceable>;
see <xref linkend="eval-mode"/> for details.</entry>
<entry>mode</entry>
<entry>-</entry>
</row>
<row>
<entry><option>--show-iface</option></entry>
<entry>Display the contents of an interface file.</entry>
<entry>mode</entry>
<entry>-</entry>
</row>
<row>
<entry><option>-M</option></entry>
<entry>Generate dependency information suitable for use in a <filename>Makefile</filename>;
see <xref linkend="makefile-dependencies"/> for details.</entry>
<entry>mode</entry>
<entry>-</entry>
</row>
<row>
<entry><option>--supported-extensions</option>, <option>--supported-languages</option></entry>
<entry>display the supported language extensions</entry>
<entry>mode</entry>
<entry>-</entry>
</row>
<row>
<entry><option>--show-options</option></entry>
<entry>display the supported command line options</entry>
<entry>mode</entry>
<entry>-</entry>
</row>
<row>
<entry><option>--info</option></entry>
<entry>display information about the compiler</entry>
<entry>mode</entry>
<entry>-</entry>
</row>
<row>
<entry><option>--version, -V</option></entry>
<entry>display GHC version</entry>
<entry>mode</entry>
<entry>-</entry>
</row>
<row>
<entry><option>--numeric-version</option></entry>
<entry>display GHC version (numeric only)</entry>
<entry>mode</entry>
<entry>-</entry>
</row>
<row>
<entry><option>--print-libdir</option></entry>
<entry>display GHC library directory</entry>
<entry>mode</entry>
<entry>-</entry>
</row>
</tbody>
</tgroup>
</informaltable>
</sect2>
<sect2>
<title>Which phases to run</title>
<para><xref linkend="options-order"/></para>
<informaltable>
<tgroup cols="4" align="left" colsep="1" rowsep="1">
<thead>
<row>
<entry>Flag</entry>
<entry>Description</entry>
<entry>Static/Dynamic</entry>
<entry>Reverse</entry>
</row>
</thead>
<tbody>
<row>
<entry><option>-E</option></entry>
<entry>Stop after preprocessing (<literal>.hspp</literal> file)</entry>
<entry>mode</entry>
<entry>-</entry>
</row>
<row>
<entry><option>-C</option></entry>
<entry>Stop after generating C (<literal>.hc</literal> file)</entry>
<entry>mode</entry>
<entry>-</entry>
</row>
<row>
<entry><option>-S</option></entry>
<entry>Stop after generating assembly (<literal>.s</literal> file)</entry>
<entry>mode</entry>
<entry>-</entry>
</row>
<row>
<entry><option>-c</option></entry>
<entry>Stop after generating object (<literal>.o</literal>) file</entry>
<entry>mode</entry>
<entry>-</entry>
</row>
<row>
<entry><option>-x</option> <replaceable>suffix</replaceable></entry>
<entry>Override default behaviour for source files</entry>
<entry>dynamic</entry>
<entry>-</entry>
</row>
</tbody>
</tgroup>
</informaltable>
</sect2>
<sect2>
<title>Redirecting output</title>
<para><xref linkend="options-output"/></para>
<informaltable>
<tgroup cols="4" align="left" colsep="1" rowsep="1">
<thead>
<row>
<entry>Flag</entry>
<entry>Description</entry>
<entry>Static/Dynamic</entry>
<entry>Reverse</entry>
</row>
</thead>
<tbody>
<row>
<entry><option>-hcsuf</option> <replaceable>suffix</replaceable></entry>
<entry>set the suffix to use for intermediate C files</entry>
<entry>dynamic</entry>
<entry>-</entry>
</row>
<row>
<entry><option>-hidir</option> <replaceable>dir</replaceable></entry>
<entry>set directory for interface files</entry>
<entry>dynamic</entry>
<entry>-</entry>
</row>
<row>
<entry><option>-hisuf</option> <replaceable>suffix</replaceable></entry>
<entry>set the suffix to use for interface files</entry>
<entry>dynamic</entry>
<entry>-</entry>
</row>
<row>
<entry><option>-o</option> <replaceable>filename</replaceable></entry>
<entry>set output filename</entry>
<entry>dynamic</entry>
<entry>-</entry>
</row>
<row>
<entry><option>-odir</option> <replaceable>dir</replaceable></entry>
<entry>set directory for object files</entry>
<entry>dynamic</entry>
<entry>-</entry>
</row>
<row>
<entry><option>-ohi</option> <replaceable>filename</replaceable></entry>
<entry>set the filename in which to put the interface</entry>
<entry>dynamic</entry>
<entry></entry>
</row>
<row>
<entry><option>-osuf</option> <replaceable>suffix</replaceable></entry>
<entry>set the output file suffix</entry>
<entry>dynamic</entry>
<entry>-</entry>
</row>
<row>
<entry><option>-stubdir</option> <replaceable>dir</replaceable></entry>
<entry>redirect FFI stub files</entry>
<entry>dynamic</entry>
<entry>-</entry>
</row>
<row>
<entry><option>-dumpdir</option> <replaceable>dir</replaceable></entry>
<entry>redirect dump files</entry>
<entry>dynamic</entry>
<entry>-</entry>
</row>
<row>
<entry><option>-outputdir</option> <replaceable>dir</replaceable></entry>
<entry>set output directory</entry>
<entry>dynamic</entry>
<entry>-</entry>
</row>
</tbody>
</tgroup>
</informaltable>
</sect2>
<sect2>
<title>Keeping intermediate files</title>
<para><xref linkend="keeping-intermediates"/></para>
<informaltable>
<tgroup cols="4" align="left" colsep="1" rowsep="1">
<thead>
<row>
<entry>Flag</entry>
<entry>Description</entry>
<entry>Static/Dynamic</entry>
<entry>Reverse</entry>
</row>
</thead>
<tbody>
<row>
<entry><option>-keep-hc-file</option> or
<option>-keep-hc-files</option></entry>
<entry>retain intermediate <literal>.hc</literal> files</entry>
<entry>dynamic</entry>
<entry>-</entry>
</row>
<row>
<entry><option>-keep-llvm-file</option> or
<option>-keep-llvm-files</option></entry>
<entry>retain intermediate LLVM <literal>.ll</literal> files</entry>
<entry>dynamic</entry>
<entry>-</entry>
</row>
<row>
<entry><option>-keep-s-file</option> or
<option>-keep-s-files</option></entry>
<entry>retain intermediate <literal>.s</literal> files</entry>
<entry>dynamic</entry>
<entry>-</entry>
</row>
<row>
<entry><option>-keep-tmp-files</option></entry>
<entry>retain all intermediate temporary files</entry>
<entry>dynamic</entry>
<entry>-</entry>
</row>
</tbody>
</tgroup>
</informaltable>
</sect2>
<sect2>
<title>Temporary files</title>
<para><xref linkend="temp-files"/></para>
<informaltable>
<tgroup cols="4" align="left" colsep="1" rowsep="1">
<thead>
<row>
<entry>Flag</entry>
<entry>Description</entry>
<entry>Static/Dynamic</entry>
<entry>Reverse</entry>
</row>
</thead>
<tbody>
<row>
<entry><option>-tmpdir</option></entry>
<entry>set the directory for temporary files</entry>
<entry>dynamic</entry>
<entry>-</entry>
</row>
</tbody>
</tgroup>
</informaltable>
</sect2>
<sect2>
<title>Finding imports</title>
<para><xref linkend="search-path"/></para>
<informaltable>
<tgroup cols="4" align="left" colsep="1" rowsep="1">
<thead>
<row>
<entry>Flag</entry>
<entry>Description</entry>
<entry>Static/Dynamic</entry>
<entry>Reverse</entry>
</row>
</thead>
<tbody>
<row>
<entry><option>-i</option><replaceable>dir1</replaceable>:<replaceable>dir2</replaceable>:...</entry>
<entry>add <replaceable>dir</replaceable>,
<replaceable>dir2</replaceable>, etc. to import path</entry>
<entry>dynamic/<literal>:set</literal></entry>
<entry>-</entry>
</row>
<row>
<entry><option>-i</option></entry>
<entry>Empty the import directory list</entry>
<entry>dynamic/<literal>:set</literal></entry>
<entry>-</entry>
</row>
</tbody>
</tgroup>
</informaltable>
</sect2>
<sect2>
<title>Interface file options</title>
<para><xref linkend="hi-options"/></para>
<informaltable>
<tgroup cols="4" align="left" colsep="1" rowsep="1">
<thead>
<row>
<entry>Flag</entry>
<entry>Description</entry>
<entry>Static/Dynamic</entry>
<entry>Reverse</entry>
</row>
</thead>
<tbody>
<row>
<entry><option>-ddump-hi</option></entry>
<entry>Dump the new interface to stdout</entry>
<entry>dynamic</entry>
<entry>-</entry>
</row>
<row>
<entry><option>-ddump-hi-diffs</option></entry>
<entry>Show the differences vs. the old interface</entry>
<entry>dynamic</entry>
<entry>-</entry>
</row>
<row>
<entry><option>-ddump-minimal-imports</option></entry>
<entry>Dump a minimal set of imports</entry>
<entry>dynamic</entry>
<entry>-</entry>
</row>
<row>
<entry><option>--show-iface</option> <replaceable>file</replaceable></entry>
<entry>See <xref linkend="modes"/>.</entry>
</row>
</tbody>
</tgroup>
</informaltable>
</sect2>
<sect2>
<title>Recompilation checking</title>
<para><xref linkend="recomp"/></para>
<informaltable>
<tgroup cols="4" align="left" colsep="1" rowsep="1">
<thead>
<row>
<entry>Flag</entry>
<entry>Description</entry>
<entry>Static/Dynamic</entry>
<entry>Reverse</entry>
</row>
</thead>
<tbody>
<row>
<entry><option>-fforce-recomp</option></entry>
<entry>Turn off recompilation checking. This is implied by any
<option>-ddump-X</option> option when compiling a single
file (i.e. when using <literal>-c</literal>).</entry>
<entry>dynamic</entry>
<entry><option>-fno-force-recomp</option></entry>
</row>
</tbody>
</tgroup>
</informaltable>
</sect2>
<sect2 id="interactive-mode-options">
<title>Interactive-mode options</title>
<para><xref linkend="ghci-dot-files"/></para>
<informaltable>
<tgroup cols="4" align="left" colsep="1" rowsep="1">
<thead>
<row>
<entry>Flag</entry>
<entry>Description</entry>
<entry>Static/Dynamic</entry>
<entry>Reverse</entry>
</row>
</thead>
<tbody>
<row>
<entry><option>-ignore-dot-ghci</option></entry>
<entry>Disable reading of <filename>.ghci</filename> files</entry>
<entry>dynamic</entry>
<entry>-</entry>
</row>
<row>
<entry><option>-ghci-script</option></entry>
<entry>Read additional <filename>.ghci</filename> files</entry>
<entry>dynamic</entry>
<entry>-</entry>
</row>
<row>
<entry><option>-fbreak-on-error</option></entry>
<entry><link linkend="ghci-debugger-exceptions">Break on uncaught exceptions and errors</link></entry>
<entry>dynamic</entry>
<entry><option>-fno-break-on-error</option></entry>
</row>
<row>
<entry><option>-fbreak-on-exception</option></entry>
<entry><link linkend="ghci-debugger-exceptions">Break on any exception thrown</link></entry>
<entry>dynamic</entry>
<entry><option>-fno-break-on-exception</option></entry>
</row>
<row>
<entry><option>-fghci-hist-size=<replaceable>n</replaceable></option></entry>
<entry><link linkend="ghci-debugger">Set the number of entries GHCi keeps for <literal>:history</literal></link></entry>
<entry>dynamic</entry>
<entry><option>(default is 50)</option></entry>
</row>
<row>
<entry><option>-fprint-evld-with-show</option></entry>
<entry><link linkend="breakpoints">Enable usage of Show instances in <literal>:print</literal></link></entry>
<entry>dynamic</entry>
<entry><option>-fno-print-evld-with-show</option></entry>
</row>
<row>
<entry><option>-fprint-bind-result</option></entry>
<entry><link linkend="ghci-stmts">Turn on printing of binding results in GHCi</link></entry>
<entry>dynamic</entry>
<entry><option>-fno-print-bind-result</option></entry>
</row>
<row>
<entry><option>-fno-print-bind-contents</option></entry>
<entry><link linkend="breakpoints">Turn off printing of binding contents in GHCi</link></entry>
<entry>dynamic</entry>
<entry>-</entry>
</row>
<row>
<entry><option>-fno-implicit-import-qualified</option></entry>
<entry><link linkend="ghci-import-qualified">Turn off
implicit qualified import of everything in GHCi</link></entry>
<entry>dynamic</entry>
<entry>-</entry>
</row>
<row>
<entry><option>-interactive-print</option></entry>
<entry><link linkend="ghci-interactive-print">Select the function
to use for printing evaluated expressions in GHCi</link></entry>
<entry>dynamic</entry>
<entry>-</entry>
</row>
</tbody>
</tgroup>
</informaltable>
</sect2>
<sect2>
<title>Packages</title>
<para><xref linkend="packages"/></para>
<informaltable>
<tgroup cols="4" align="left" colsep="1" rowsep="1">
<thead>
<row>
<entry>Flag</entry>
<entry>Description</entry>
<entry>Static/Dynamic</entry>
<entry>Reverse</entry>
</row>
</thead>
<tbody>
<row>
<entry><option>-this-package-key</option> <replaceable>P</replaceable></entry>
<entry>Compile to be part of package <replaceable>P</replaceable></entry>
<entry>dynamic</entry>
<entry>-</entry>
</row>
<row>
<entry><option>-package</option> <replaceable>P</replaceable></entry>
<entry>Expose package <replaceable>P</replaceable></entry>
<entry>dynamic/<literal>:set</literal></entry>
<entry>-</entry>
</row>
<row>
<entry><option>-hide-all-packages</option></entry>
<entry>Hide all packages by default</entry>
<entry>dynamic</entry>
<entry>-</entry>
</row>
<row>
<entry><option>-hide-package</option> <replaceable>name</replaceable></entry>
<entry>Hide package <replaceable>P</replaceable></entry>
<entry>dynamic/<literal>:set</literal></entry>
<entry>-</entry>
</row>
<row>
<entry><option>-ignore-package</option> <replaceable>name</replaceable></entry>
<entry>Ignore package <replaceable>P</replaceable></entry>
<entry>dynamic/<literal>:set</literal></entry>
<entry>-</entry>
</row>
<row>
<entry><option>-package-db</option> <replaceable>file</replaceable></entry>
<entry>Add <replaceable>file</replaceable> to the package db stack.</entry>
<entry>dynamic</entry>
<entry>-</entry>
</row>
<row>
<entry><option>-clear-package-db</option></entry>
<entry>Clear the package db stack.</entry>
<entry>dynamic</entry>
<entry>-</entry>
</row>
<row>
<entry><option>-no-global-package-db</option></entry>
<entry>Remove the global package db from the stack.</entry>
<entry>dynamic</entry>
<entry>-</entry>
</row>
<row>
<entry><option>-global-package-db</option></entry>
<entry>Add the global package db to the stack.</entry>
<entry>dynamic</entry>
<entry>-</entry>
</row>
<row>
<entry><option>-no-user-package-db</option></entry>
<entry>Remove the user's package db from the stack.</entry>
<entry>dynamic</entry>
<entry>-</entry>
</row>
<row>
<entry><option>-user-package-db</option></entry>
<entry>Add the user's package db to the stack.</entry>
<entry>dynamic</entry>
<entry>-</entry>
</row>
<row>
<entry><option>-no-auto-link-packages</option></entry>
<entry>Don't automatically link in the base and rts packages.</entry>
<entry>dynamic</entry>
<entry>-</entry>
</row>
<row>
<entry><option>-trust</option> <replaceable>P</replaceable></entry>
<entry>Expose package <replaceable>P</replaceable> and set it to be
trusted</entry>
<entry>dynamic/<literal>:set</literal></entry>
<entry>-</entry>
</row>
<row>
<entry><option>-distrust</option> <replaceable>P</replaceable></entry>
<entry>Expose package <replaceable>P</replaceable> and set it to be
distrusted</entry>
<entry>dynamic/<literal>:set</literal></entry>
<entry>-</entry>
</row>
<row>
<entry><option>-distrust-all</option> </entry>
<entry>Distrust all packages by default</entry>
<entry>dynamic/<literal>:set</literal></entry>
<entry>-</entry>
</row>
</tbody>
</tgroup>
</informaltable>
</sect2>
<sect2>
<title>Language options</title>
<para>Language options can be enabled either by a command-line option
<option>-Xblah</option>, or by a <literal>{-# LANGUAGE blah #-}</literal>
pragma in the file itself. See <xref linkend="options-language"/>. Some
options are enabled using <option>-f*</option> flags.</para>
<informaltable>
<tgroup cols="4" align="left" colsep="1" rowsep="1">
<thead>
<row>
<entry>Flag</entry>
<entry>Description</entry>
<entry>Static/Dynamic</entry>
<entry>Reverse</entry>
</row>
</thead>
<tbody>
<row>
<entry><option>-fcontext-stack=</option><replaceable>n</replaceable></entry>
<entry>set the <link linkend="undecidable-instances">limit for type-class context reduction</link>. Default is 100.</entry>
<entry>dynamic</entry>
<entry></entry>
</row>
<row>
<entry><option>-fglasgow-exts</option></entry>
<entry>Deprecated. Enable most language extensions; see <xref linkend="options-language"/> for exactly which ones.</entry>
<entry>dynamic</entry>
<entry><option>-fno-glasgow-exts</option></entry>
</row>
<row>
<entry><option>-firrefutable-tuples</option></entry>
<entry>Make tuple pattern matching irrefutable</entry>
<entry>dynamic</entry>
<entry><option>-fno-irrefutable-tuples</option></entry>
</row>
<row>
<entry><option>-fpackage-trust</option></entry>
<entry>Enable <link linkend="safe-haskell">Safe Haskell</link> trusted package requirement for trustworthy modules.</entry>
<entry>dynamic</entry>
<entry><option>-</option></entry>
</row>
<row>
<entry><option>-ftype-function-depth=</option><replaceable>n</replaceable></entry>
<entry>set the <link linkend="type-families">limit for type function reductions</link>. Default is 200.</entry>
<entry>dynamic</entry>
<entry></entry>
</row>
<row>
<entry><option>-XAllowAmbiguousTypes</option></entry>
<entry>Allow the user to write <link linkend="ambiguity">ambiguous types</link>,
and the type inference engine to infer them.
</entry>
<entry>dynamic</entry>
<entry><option>-XNoAllowAmbiguousTypes</option></entry>
</row>
<row>
<entry><option>-XArrows</option></entry>
<entry>Enable <link linkend="arrow-notation">arrow
notation</link> extension</entry>
<entry>dynamic</entry>
<entry><option>-XNoArrows</option></entry>
</row>
<row>
<entry><option>-XAutoDeriveTypeable</option></entry>
<entry>Automatically <link linkend="deriving-typeable">derive Typeable instances for every datatype and type class declaration</link>.
Implies <option>-XDeriveDataTypeable</option>.</entry>
<entry>dynamic</entry>
<entry><option>-XNoAutoDeriveTypeable</option></entry>
</row>
<row>
<entry><option>-XBangPatterns</option></entry>
<entry>Enable <link linkend="bang-patterns">bang patterns</link>.</entry>
<entry>dynamic</entry>
<entry><option>-XNoBangPatterns</option></entry>
</row>
<row>
<entry><option>-XBinaryLiterals</option></entry>
<entry>Enable support for <link linkend="binary-literals">binary literals</link>.</entry>
<entry>dynamic</entry>
<entry><option>-XNoBinaryLiterals</option></entry>
</row>
<row>
<entry><option>-XCApiFFI</option></entry>
<entry>Enable <link linkend="ffi-capi">the CAPI calling convention</link>.</entry>
<entry>dynamic</entry>
<entry><option>-XNoCAPIFFI</option></entry>
</row>
<row>
<entry><option>-XConstrainedClassMethods</option></entry>
<entry>Enable <link linkend="class-method-types">constrained class methods</link>.</entry>
<entry>dynamic</entry>
<entry><option>-XNoConstrainedClassMethods</option></entry>
</row>
<row>
<entry><option>-XConstraintKinds</option></entry>
<entry>Enable a <link linkend="constraint-kind">kind of constraints</link>.</entry>
<entry>dynamic</entry>
<entry><option>-XNoConstraintKinds</option></entry>
</row>
<row>
<entry><option>-XCPP</option></entry>
<entry>Enable the <link linkend="c-pre-processor">C preprocessor</link>.</entry>
<entry>dynamic</entry>
<entry><option>-XNoCPP</option></entry>
</row>
<row>
<entry><option>-XDataKinds</option></entry>
<entry>Enable <link linkend="promotion">datatype promotion</link>.</entry>
<entry>dynamic</entry>
<entry><option>-XNoDataKinds</option></entry>
</row>
<row>
<entry><option>-XDefaultSignatures</option></entry>
<entry>Enable <link linkend="class-default-signatures">default signatures</link>.</entry>
<entry>dynamic</entry>
<entry><option>-XNoDefaultSignatures</option></entry>
</row>
<row>
<entry><option>-XDeriveAnyClass</option></entry>
<entry>Enable <link linkend="derive-any-class">deriving for any
class</link>.</entry>
<entry>dynamic</entry>
<entry><option>-XNoDeriveAnyClass</option></entry>
</row>
<row>
<entry><option>-XDeriveDataTypeable</option></entry>
<entry>Enable <link linkend="deriving-typeable">deriving for the Data and Typeable classes</link>.
Implied by <option>-XAutoDeriveTypeable</option>.</entry>
<entry>dynamic</entry>
<entry><option>-XNoDeriveDataTypeable</option></entry>
</row>
<row>
<entry><option>-XDeriveFunctor</option></entry>
<entry>Enable <link linkend="deriving-extra">deriving for the Functor class</link>.
Implied by <option>-XDeriveTraversable</option>.</entry>
<entry>dynamic</entry>
<entry><option>-XNoDeriveFunctor</option></entry>
</row>
<row>
<entry><option>-XDeriveFoldable</option></entry>
<entry>Enable <link linkend="deriving-extra">deriving for the Foldable class</link>.
Implied by <option>-XDeriveTraversable</option>.</entry>
<entry>dynamic</entry>
<entry><option>-XNoDeriveFoldable</option></entry>
</row>
<row>
<entry><option>-XDeriveGeneric</option></entry>
<entry>Enable <link linkend="deriving-typeable">deriving for the Generic class</link>.</entry>
<entry>dynamic</entry>
<entry><option>-XNoDeriveGeneric</option></entry>
</row>
<row>
<entry><option>-XDeriveTraversable</option></entry>
<entry>Enable <link linkend="deriving-extra">deriving for the Traversable class</link>.
Implies <option>-XDeriveFunctor</option> and <option>-XDeriveFoldable</option>.</entry>
<entry>dynamic</entry>
<entry><option>-XNoDeriveTraversable</option></entry>
</row>
<row>
<entry><option>-XDisambiguateRecordFields</option></entry>
<entry>Enable <link linkend="disambiguate-fields">record field disambiguation</link>.
Implied by <option>-XRecordWildCards</option>.</entry>
<entry>dynamic</entry>
<entry><option>-XNoDisambiguateRecordFields</option></entry>
</row>
<row>
<entry><option>-XEmptyCase</option></entry>
<entry>Allow <link linkend="empty-case">empty case alternatives</link>.</entry>
<entry>dynamic</entry>
<entry><option>-XNoEmptyCase</option></entry>
</row>
<row>
<entry><option>-XEmptyDataDecls</option></entry>
<entry>Enable empty data declarations.</entry>
<entry>dynamic</entry>
<entry><option>-XNoEmptyDataDecls</option></entry>
</row>
<row>
<entry><option>-XExistentialQuantification</option></entry>
<entry>Enable <link linkend="existential-quantification">existential quantification</link>.</entry>
<entry>dynamic</entry>
<entry><option>-XNoExistentialQuantification</option></entry>
</row>
<row>
<entry><option>-XExplicitForAll</option></entry>
<entry>Enable <link linkend="explicit-foralls">explicit universal quantification</link>.
Implied by <option>-XScopedTypeVariables</option>,
<option>-XLiberalTypeSynonyms</option>,
<option>-XRankNTypes</option> and
<option>-XExistentialQuantification</option>.
</entry>
<entry>dynamic</entry>
<entry><option>-XNoExplicitForAll</option></entry>
</row>
<row>
<entry><option>-XExplicitNamespaces</option></entry>
<entry>Enable using the keyword <literal>type</literal> to specify the namespace of
entries in imports and exports (<xref linkend="explicit-namespaces"/>).
Implied by <option>-XTypeOperators</option> and <option>-XTypeFamilies</option>.</entry>
<entry>dynamic</entry>
<entry><option>-XNoExplicitNamespaces</option></entry>
</row>
<row>
<entry><option>-XExtendedDefaultRules</option></entry>
<entry>Use GHCi's <link linkend="extended-default-rules">extended default rules</link> in a normal module.</entry>
<entry>dynamic</entry>
<entry><option>-XNoExtendedDefaultRules</option></entry>
</row>
<row>
<entry><option>-XFlexibleContexts</option></entry>
<entry>Enable <link linkend="flexible-contexts">flexible contexts</link>.
Implied by <option>-XImplicitParams</option>.</entry>
<entry>dynamic</entry>
<entry><option>-XNoFlexibleContexts</option></entry>
</row>
<row>
<entry><option>-XFlexibleInstances</option></entry>
<entry>Enable <link linkend="instance-rules">flexible instances</link>.
Implies <option>-XTypeSynonymInstances</option>. Implied by <option>-XImplicitParams</option>.</entry>
<entry>dynamic</entry>
<entry><option>-XNoFlexibleInstances</option></entry>
</row>
<row>
<entry><option>-XForeignFunctionInterface</option></entry>
<entry>Enable <link linkend="ffi">foreign function interface</link>.</entry>
<entry>dynamic</entry>
<entry><option>-XNoForeignFunctionInterface</option></entry>
</row>
<row>
<entry><option>-XFunctionalDependencies</option></entry>
<entry>Enable <link linkend="functional-dependencies">functional dependencies</link>.
Implies <option>-XMultiParamTypeClasses</option>.</entry>
<entry>dynamic</entry>
<entry><option>-XNoFunctionalDependencies</option></entry>
</row>
<row>
<entry><option>-XGADTs</option></entry>
<entry>Enable <link linkend="gadt">generalised algebraic data types</link>.
Implies <option>-XGADTSyntax</option> and <option>-XMonoLocalBinds</option>.</entry>
<entry>dynamic</entry>
<entry><option>-XNoGADTs</option></entry>
</row>
<row>
<entry><option>-XGADTSyntax</option></entry>
<entry>Enable <link linkend="gadt-style">generalised algebraic data type syntax</link>.
</entry>
<entry>dynamic</entry>
<entry><option>-XNoGADTSyntax</option></entry>
</row>
<row>
<entry><option>-XGeneralizedNewtypeDeriving</option></entry>
<entry>Enable <link linkend="newtype-deriving">newtype deriving</link>.</entry>
<entry>dynamic</entry>
<entry><option>-XNoGeneralizedNewtypeDeriving</option></entry>
</row>
<row>
<entry><option>-XGenerics</option></entry>
<entry>Deprecated, does nothing. No longer enables <link linkend="generic-classes">generic classes</link>.
See also GHC's support for
<link linkend="generic-programming">generic programming</link>.</entry>
<entry>dynamic</entry>
<entry><option>-XNoGenerics</option></entry>
</row>
<row>
<entry><option>-XImplicitParams</option></entry>
<entry>Enable <link linkend="implicit-parameters">Implicit Parameters</link>.
Implies <option>-XFlexibleContexts</option> and <option>-XFlexibleInstances</option>.</entry>
<entry>dynamic</entry>
<entry><option>-XNoImplicitParams</option></entry>
</row>
<row>
<entry><option>-XNoImplicitPrelude</option></entry>
<entry>Don't implicitly <literal>import Prelude</literal>.
Implied by <option>-XRebindableSyntax</option>.</entry>
<entry>dynamic</entry>
<entry><option>-XImplicitPrelude</option></entry>
</row>
<row>
<entry><option>-XImpredicativeTypes</option></entry>
<entry>Enable <link linkend="impredicative-polymorphism">impredicative types</link>.
Implies <option>-XRankNTypes</option>.</entry>
<entry>dynamic</entry>
<entry><option>-XNoImpredicativeTypes</option></entry>
</row>
<row>
<entry><option>-XIncoherentInstances</option></entry>
<entry>Enable <link linkend="instance-overlap">incoherent instances</link>.
Implies <option>-XOverlappingInstances</option>.</entry>
<entry>dynamic</entry>
<entry><option>-XNoIncoherentInstances</option></entry>
</row>
<row>
<entry><option>-XInstanceSigs</option></entry>
<entry>Enable <link linkend="instance-sigs">instance signatures</link>.</entry>
<entry>dynamic</entry>
<entry><option>-XNoInstanceSigs</option></entry>
</row>
<row>
<entry><option>-XInterruptibleFFI</option></entry>
<entry>Enable interruptible FFI.</entry>
<entry>dynamic</entry>
<entry><option>-XNoInterruptibleFFI</option></entry>
</row>
<row>
<entry><option>-XKindSignatures</option></entry>
<entry>Enable <link linkend="kinding">kind signatures</link>.
Implied by <option>-XTypeFamilies</option> and <option>-XPolyKinds</option>.</entry>
<entry>dynamic</entry>
<entry><option>-XNoKindSignatures</option></entry>
</row>