1GHC(1) Glasgow Haskell Compiler GHC(1)
2
6 GHC - the Glasgow Haskell Compiler
7
11 ghc [option|filename]...
12 ghci [option|filename]...
13
16 This manual page documents briefly the ghc and ghci commands. Note
17 that ghci is not yet available on all architectures. Extensive docu‐
18 mentation is available in various other formats including DVI, Post‐
19 Script and HTML; see below.
20 Each of GHC's command line options is classified as either static or
23 dynamic. A static flag may only be specified on the command line,
24 whereas a dynamic flag may also be given in an OPTIONS pragma in a
25 source file or set from the GHCi command-line with :set.
26 As a rule of thumb, all the language options are dynamic, as are the
28 warning options and the debugging options.
29 The rest are static, with the notable exceptions of -v, -cpp, -fasm,
31 -fvia-C, and -#include. The OPTIONS sections lists the status of each
32 flag.
33 Common suffixes of file names for Haskell are:
36 .hs Haskell source code; preprocess, compile
38 .lhs literate Haskell source; unlit, preprocess, compile
40 .hi Interface file; contains information about exported symbols
42 .hc intermediate C files
44 .x_o way x object files; common ways are: p, u, s
46 .x_hi way x interface files
48
52 Help and verbosity options
53 -? -help -n -v -vn -V --supported-languages --info --version
54 --numeric-version --print-libdir -ferror-spans -Hsize -Rghc-timing
55 Which phases to run
58 -E -C -S -c -x suffix
59 Alternative modes of operation
62 --interactive --make -e expr -M
63 Redirecting output
66 -hcsuf suffix -hidir dir -hisuf suffix -o filename -odir dir -ohi
67 filename -osuf suffix -stubdir dir -outputdir dir
68 Keeping intermediate files
71 -keep-hc-file or
72 -keep-hc-files -keep-s-file or
73 -keep-s-files -keep-raw-s-file or
74 -keep-raw-s-files -keep-tmp-files
75 Temporary files
78 -tmpdir
79 Finding imports
82 -idir1:dir2:... -i
83 Interface file options
86 -ddump-hi -ddump-hi-diffs -ddump-minimal-imports --show-iface file
87 Recompilation checking
90 -fforce-recomp -fno-force-recomp
91 Interactive-mode options
94 -ignore-dot-ghci -read-dot-ghci -fbreak-on-exception
95 -fno-break-on-exception -fbreak-on-error -fno-break-on-error
96 -fprint-evld-with-show -fno-print-evld-with-show -fprint-bind-result
97 -fno-print-bind-result -fno-print-bind-contents
98 -fno-implicit-import-qualified
99 Packages
102 -package-name P -package P -hide-all-packages -hide-package name
103 -ignore-package name -package-conf file -no-user-package-conf
104 -no-auto-link-packages
105 Language options
108 -fglasgow-exts -fno-glasgow-exts -XOverlappingInstances
109 -XNoOverlappingInstances -XIncoherentInstances -XNoIncoherentInstances
110 -XUndecidableInstances -XNoUndecidableInstances -fcontext-stack=Nn
111 -XArrows -XNoArrows -XDisambiguateRecordFields
112 -XNoDisambiguateRecordFields -XForeignFunctionInterface
113 -XNoForeignFunctionInterface -XGenerics -XNoGenerics -XImplicitParams
114 -XNoImplicitParams -firrefutable-tuples -fno-irrefutable-tuples
115 -XNoImplicitPrelude -XImplicitPrelude -XNoMonomorphismRestriction
116 -XMonomorphismRrestriction -XNoNPlusKPatterns -XNPlusKPatterns
117 -XNoMonoPatBinds -XMonoPatBinds -XRelaxedPolyRec -XNoRelaxedPolyRec
118 -XExtendedDefaultRules -XNoExtendedDefaultRules -XOverloadedStrings
119 -XNoOverloadedStrings -XGADTs -XNoGADTs -XTypeFamilies
120 -XNoTypeFamilies -XScopedTypeVariables -XNoScopedTypeVariables
121 -XMonoLocalBinds -XNoMonoLocalBinds -XTemplateHaskell
122 -XNoTemplateHaskell -XQuasiQuotes -XNoQuasiQuotes -XBangPatterns
123 -XNoBangPatterns -XCPP -XNoCPP -XPatternGuards -XNoPatternGuards
124 -XViewPatterns -XNoViewPatterns -XUnicodeSyntax -XNoUnicodeSyntax
125 -XMagicHash -XNoMagicHash -XNewQualifiedOperators
126 -XNoNewQualifiedOperators -XExplicitForALl -XNoExplicitForAll
127 -XPolymorphicComponents -XNoPolymorphicComponents -XRank2Types
128 -XNoRank2Types -XRankNTypes -XNoRankNTypes -XImpredicativeTypes
129 -XNoImpredicativeTypes -XExistentialQuantification
130 -XNoExistentialQuantification -XKindSignatures -XNoKindSignatures
131 -XEmptyDataDecls -XNoEmptyDataDecls -XParallelListComp
132 -XNoParallelListComp -XTransformListComp -XNoTransformListComp
133 -XUnliftedFFITypes -XNoUnliftedFFITypes -XLiberalTypeSynonyms
134 -XNoLiberalTypeSynonyms -XTypeOperators -XNoTypeOperators -XDoRec
135 -XNoDoRec -XRecursiveDo -XNoRecursiveDo -XPArr -XNoPArr
136 -XRecordWildCards -XNoRecordWildCards -XNamedFieldPuns
137 -XNoNamedFieldPuns -XDisambiguateRecordFields
138 -XNoDisambiguateRecordFields -XUnboxedTuples -XNoUnboxedTuples
139 -XStandaloneDeriving -XNoStandaloneDeriving -XDeriveDataTypeable
140 -XNoDeriveDataTypeable -XGeneralizedNewtypeDeriving
141 -XNoGeneralizedNewtypeDeriving -XTypeSynonymInstances
142 -XNoTypeSynonymInstances -XFlexibleContexts -XNoFlexibleContexts
143 -XFlexibleInstances -XNoFlexibleInstances -XConstrainedClassMethods
144 -XNoConstrainedClassMethods -XMultiParamTypeClasses
145 -XNoMultiParamTypeClasses -XFunctionalDependencies
146 -XNoFunctionalDependencies -XPackageImports -XNoPackageImports
147 Warnings
150 -W -w -w -Wall -w -Werror -Wwarn -fwarn-unrecognised-pragmas
151 -fno-warn-unrecognised-pragmas -fwarn-warnings-deprecations
152 -fno-warn-warnings-deprecations -fwarn-deprecated-flags
153 -fno-warn-deprecated-flags -fwarn-duplicate-exports
154 -fno-warn-duplicate-exports -fwarn-hi-shadowing -fno-warn-hi-shadowing
155 -fwarn-implicit-prelude -fno-warn-implicit-prelude
156 -fwarn-incomplete-patterns -fno-warn-incomplete-patterns
157 -fwarn-incomplete-record-updates -fno-warn-incomplete-record-updates
158 -fwarn-missing-fields -fno-warn-missing-fields -fwarn-missing-methods
159 -fno-warn-missing-methods -fwarn-missing-signatures
160 -fno-warn-missing-signatures -fwarn-name-shadowing
161 -fno-warn-name-shadowing -fwarn-orphans -fno-warn-orphans
162 -fwarn-overlapping-patterns -fno-warn-overlapping-patterns
163 -fwarn-simple-patterns -fno-warn-simple-patterns -fwarn-tabs
164 -fno-warn-tabs -fwarn-type-defaults -fno-warn-type-defaults
165 -fwarn-monomorphism-restriction -fno-warn-monomorphism-restriction
166 -fwarn-unused-binds -fno-warn-unused-binds -fwarn-unused-imports
167 -fno-warn-unused-imports -fwarn-unused-matches
168 -fno-warn-unused-matches -fwarn-unused-do-bind
169 -fno-warn-unused-do-bind -fwarn-wrong-do-bind -fno-warn-wrong-do-bind
170 Optimisation levels
173 -O -O0 -On -O0
174 Individual optimisations
177 -fcase-merge -fno-case-merge -fdicts-strict -fno-dicts-strict
178 -fmethod-sharing -fno-method-sharing -fdo-eta-reduction
179 -fno-do-eta-reduction -fdo-lambda-eta-expansion
180 -fno-do-lambda-eta-expansion -fexcess-precision -fno-excess-precision
181 -fignore-asserts -fno-ignore-asserts -fignore-interface-pragmas
182 -fno-ignore-interface-pragmas -fomit-interface-pragmas
183 -fno-omit-interface-pragmas -fmax-worker-args -fsimplifier-phases
184 -fmax-simplifier-iterations -fno-state-hack -fcse -ffull-laziness
185 -frewrite-rules -fno-rewrite-rules -fstrictness -fspec-constr
186 -fspec-constr-threshold=n -fno-spec-constr-threshold
187 -fspec-constr-count=n -fno-spec-constr-count -fliberate-case
188 -fstatic-argument-transformation -fliberate-case-threshold=n
189 -fno-liberate-case-threshold -funbox-strict-fields
190 -fno-unbox-strict-fields -funfolding-creation-threshold
191 -fno-unfolding-creation-threshold -funfolding-fun-discount
192 -fno-unfolding-fun-discount -funfolding-keeness-factor
193 -fno-unfolding-keeness-factor -funfolding-use-threshold
194 -fno-unfolding-use-threshold -fno-pre-inlining -feager-blackholing
195 Profiling options
198 -auto -no-auto -auto-all -no-auto-all -caf-all -no-caf-all -prof
199 -ticky
200 Program coverage options
203 -fhpc -hpcdir dir
204 Haskell pre-processor options
207 -F
208 C pre-processor options
211 -cpp -Dsymbol=value -U -Usymbol -Idir
212 Code generation options
215 -fasm -fvia-C -fno-code -fbyte-code -fobject-code
216 Linking options
219 -shared -fPIC -dynamic -dynload -framework name -framework-path
220 name -llib -Ldir -main-is --mk-dll -no-hs-main -no-link
221 -split-objs -static -threaded -debug -eventlog -fno-gen-manifest
222 -fno-embed-manifest -fno-shared-implib
223 Replacing phases
226 -pgmL cmd -pgmP cmd -pgmc cmd -pgmm cmd -pgms cmd -pgma cmd -pgml
227 cmd -pgmdll cmd -pgmF cmd -pgmwindres cmd
228 Forcing options to particular phases
231 -optL option -optP option -optF option -optc option -optm option
232 -opta option -optl option -optdll option -optwindres option
233 Platform-specific options
236 -monly-[432]-regs
237 External core file options
240 -fext-core
241 Compiler debugging options
244 -dcore-lint -ddump-asm -ddump-bcos -ddump-cmm -ddump-cpranal
245 -ddump-cse -ddump-deriv -ddump-ds -ddump-flatC -ddump-foreign
246 -ddump-hpc -ddump-inlinings -ddump-occur-anal -ddump-opt-cmm
247 -ddump-parsed -ddump-prep -ddump-rn -ddump-rules -ddump-simpl
248 -ddump-simpl-phases -ddump-simpl-iterations -ddump-spec
249 -ddump-splices -ddump-stg -ddump-stranal -ddump-tc -ddump-types
250 -ddump-worker-wrapper -ddump-if-trace -ddump-tc-trace
251 -ddump-rn-trace -ddump-rn-stats -ddump-simpl-stats -dno-debug-output
252 -dppr-debug -dsuppress-uniques -dppr-noprags -dppr-user-length
253 -dsource-stats -dcmm-lint -dstg-lint -dstg-stats
254 -dverbose-core2core -dverbose-stg2stg -dshow-passes
255 -dfaststring-stats
256 Misc compiler options
259 -fno-hi-version-check -dno-black-holing -fhistory-size
260 -funregisterised -fno-asm-mangling
261
265 -? help
266 [mode]
267 -help help
270 [mode]
271 -n do a dry run
274 [dynamic]
275 -v verbose mode (equivalent to -v3)
278 [dynamic]
279 -vn set verbosity level
282 [dynamic]
283 -V display GHC version
286 [mode]
287 --supported-languages
290 display the supported language extensions
291 [mode]
292 --info display information about the compiler
295 [mode]
296 --version
299 display GHC version
300 [mode]
301 --numeric-version
304 display GHC version (numeric only)
305 [mode]
306 --print-libdir
309 display GHC library directory
310 [mode]
311 -ferror-spans
314 output full span in error messages
315 [static]
316 -Hsize Set the minimum heap size to size
319 [static]
320 -Rghc-timing
323 Summarise timing stats for GHC (same as +RTS -tstderr)
324 [static]
325
329 -E Stop after preprocessing (.hspp file)
330 [mode]
331 -C Stop after generating C (.hc file)
334 [mode]
335 -S Stop after generating assembly (.s file)
338 [mode]
339 -c Do not link
342 [dynamic]
343 -x suffix
346 Override default behaviour for source files
347 [static]
348
352 --interactive
353 Interactive mode - normally used by just running ghci; see for
354 details.
355 [mode]
356 --make Build a multi-module Haskell program, automatically figuring out
359 dependencies. Likely to be much easier, and faster, than using
360 make; see for details..
361 [mode]
362 -e expr
365 Evaluate expr; see for details.
366 [mode]
367 -M Generate dependency information suitable for use in a Makefile;
370 see for details.
371 [mode]
372
376 -hcsuf suffix
377 set the suffix to use for intermediate C files
378 [dynamic]
379 -hidir dir
382 set directory for interface files
383 [dynamic]
384 -hisuf suffix
387 set the suffix to use for interface files
388 [dynamic]
389 -o filename
392 set output filename
393 [dynamic]
394 -odir dir
397 set directory for object files
398 [dynamic]
399 -ohi filename
402 set the filename in which to put the interface
403 [dynamic]
404 -osuf suffix
407 set the output file suffix
408 [dynamic]
409 -stubdir dir
412 redirect FFi stub files
413 [dynamic]
414 -outputdir dir
417 set output directory
418 [dynamic]
419
423 -keep-hc-file or
424 -keep-hc-files retain intermediate .hc files
425 [dynamic]
426 -keep-s-file or
429 -keep-s-files retain intermediate .s files
430 [dynamic]
431 -keep-raw-s-file or
434 -keep-raw-s-files retain intermediate .raw_s
435 files
436 [dynamic]
437 -keep-tmp-files
440 retain all intermediate temporary files
441 [dynamic]
442
446 -tmpdir
447 set the directory for temporary files
448 [dynamic]
449
453 -idir1:dir2:...
454 add dir, dir2, etc. to import path
455 [static/:set]
456 -i Empty the import directory list
459 [static/:set]
460
464 -ddump-hi
465 Dump the new interface to stdout
466 [dynamic]
467 -ddump-hi-diffs
470 Show the differences vs. the old interface
471 [dynamic]
472 -ddump-minimal-imports
475 Dump a minimal set of imports
476 [dynamic]
477 --show-iface file
480 See .
481 []
482
486 -fforce-recomp
487 Turn off recompilation checking; implied by any -ddump-X option
488 [dynamic]
489
493 -ignore-dot-ghci
494 Disable reading of .ghci files
495 [static]
496 -read-dot-ghci
499 Enable reading of .ghci files
500 [static]
501 -fbreak-on-exception
504 Break on any exception thrown
505 [dynamic]
506 -fbreak-on-error
509 Break on uncaught exceptions and errors
510 [dynamic]
511 -fprint-evld-with-show
514 Enable usage of Show instances in :print
515 [dynamic]
516 -fprint-bind-result
519 Turn on printing of binding results in GHCi
520 [dynamic]
521 -fno-print-bind-contents
524 Turn off printing of binding contents in GHCi
525 [dynamic]
526 -fno-implicit-import-qualified
529 Turn off implicit qualified import of everything in GHCi
530 [dynamic]
531
535 -package-name P
536 Compile to be part of package P
537 [dynamic]
538 -package P
541 Expose package P
542 [static/:set]
543 -hide-all-packages
546 Hide all packages by default
547 [static]
548 -hide-package name
551 Hide package P
552 [static/:set]
553 -ignore-package name
556 Ignore package P
557 [static/:set]
558 -package-conf file
561 Load more packages from file
562 [static]
563 -no-user-package-conf
566 Don't load the user's package config file.
567 [static]
568 -no-auto-link-packages
571 Don't automatically link in the haskell98 package.
572 [dynamic]
573
577 -fglasgow-exts
578 Enable most language extensions
579 [dynamic]
580 -XOverlappingInstances
583 Enable overlapping instances
584 [dynamic]
585 -XIncoherentInstances
588 Enable incoherent instances. Implies -XOverlappingInstances
589 [dynamic]
590 -XUndecidableInstances
593 Enable undecidable instances
594 [dynamic]
595 -fcontext-stack=Nn
598 set the limit for context reduction. Default is 20.
599 [dynamic]
600 -XArrows
603 Enable arrow notation extension
604 [dynamic]
605 -XDisambiguateRecordFields
608 Enable record field disambiguation
609 [dynamic]
610 -XForeignFunctionInterface
613 Enable foreign function interface (implied by -fglasgow-exts)
614 [dynamic]
615 -XGenerics
618 Enable generic classes
619 [dynamic]
620 -XImplicitParams
623 Enable Implicit Parameters. Implied by -fglasgow-exts.
624 [dynamic]
625 -firrefutable-tuples
628 Make tuple pattern matching irrefutable
629 [dynamic]
630 -XNoImplicitPrelude
633 Don't implicitly import Prelude
634 [dynamic]
635 -XNoMonomorphismRestriction
638 Disable the monomorphism restriction
639 [dynamic]
640 -XNoNPlusKPatterns
643 Disable support for n+k patterns
644 [dynamic]
645 -XNoMonoPatBinds
648 Make pattern bindings polymorphic
649 [dynamic]
650 -XRelaxedPolyRec
653 Relaxed checking for mutually-recursive polymorphic functions
654 [dynamic]
655 -XExtendedDefaultRules
658 Use GHCi's extended default rules in a normal module
659 [dynamic]
660 -XOverloadedStrings
663 Enable overloaded string literals.
664 [dynamic]
665 -XGADTs
668 Enable generalised algebraic data types.
669 [dynamic]
670 -XTypeFamilies
673 Enable type families.
674 [dynamic]
675 -XScopedTypeVariables
678 Enable lexically-scoped type variables. Implied by -fglas‐
679 gow-exts.
680 [dynamic]
681 -XMonoLocalBinds
684 Enable do not generalise local bindings.
685 [dynamic]
686 -XTemplateHaskell
689 Enable Template Haskell. No longer implied by -fglasgow-exts.
690 [dynamic]
691 -XQuasiQuotes
694 Enable quasiquotation.
695 [dynamic]
696 -XBangPatterns
699 Enable bang patterns.
700 [dynamic]
701 -XCPP Enable the C preprocessor.
704 [dynamic]
705 -XPatternGuards
708 Enable pattern guards.
709 [dynamic]
710 -XViewPatterns
713 Enable view patterns.
714 [dynamic]
715 -XUnicodeSyntax
718 Enable unicode syntax.
719 [dynamic]
720 -XMagicHash
723 Allow "#" as a postfix modifier on identifiers.
724 [dynamic]
725 -XNewQualifiedOperators
728 Enable new qualified operator syntax
729 [dynamic]
730 -XExplicitForALl
733 Enable explicit universal quantification. Implied by -XScoped‐
734 TypeVariables, -XLiberalTypeSynonyms, -XRank2Types, -XRankN‐
735 Types, -XPolymorphicComponents, -XExistentialQuantification
736 [dynamic]
737 -XPolymorphicComponents
740 Enable polymorphic components for data constructors.
741 [dynamic]
742 -XRank2Types
745 Enable rank-2 types.
746 [dynamic]
747 -XRankNTypes
750 Enable rank-N types.
751 [dynamic]
752 -XImpredicativeTypes
755 Enable impredicative types.
756 [dynamic]
757 -XExistentialQuantification
760 Enable existential quantification.
761 [dynamic]
762 -XKindSignatures
765 Enable kind signatures.
766 [dynamic]
767 -XEmptyDataDecls
770 Enable empty data declarations.
771 [dynamic]
772 -XParallelListComp
775 Enable parallel list comprehensions.
776 [dynamic]
777 -XTransformListComp
780 Enable generalised list comprehensions.
781 [dynamic]
782 -XUnliftedFFITypes
785 Enable unlifted FFI types.
786 [dynamic]
787 -XLiberalTypeSynonyms
790 Enable liberalised type synonyms.
791 [dynamic]
792 -XTypeOperators
795 Enable type operators.
796 [dynamic]
797 -XDoRec
800 Enable recursive do notation.
801 [dynamic]
802 -XRecursiveDo
805 Enable recursive do (mdo) notation. This is deprecated; please
806 use recursive do notation instead.
807 [dynamic]
808 -XPArr Enable parallel arrays.
811 [dynamic]
812 -XRecordWildCards
815 Enable record wildcards.
816 [dynamic]
817 -XNamedFieldPuns
820 Enable record puns.
821 [dynamic]
822 -XDisambiguateRecordFields
825 Enable record field disambiguation.
826 [dynamic]
827 -XUnboxedTuples
830 Enable unboxed tuples.
831 [dynamic]
832 -XStandaloneDeriving
835 Enable standalone deriving.
836 [dynamic]
837 -XDeriveDataTypeable
840 Enable deriving for the Data and Typeable classes.
841 [dynamic]
842 -XGeneralizedNewtypeDeriving
845 Enable newtype deriving.
846 [dynamic]
847 -XTypeSynonymInstances
850 Enable type synonyms in instance heads.
851 [dynamic]
852 -XFlexibleContexts
855 Enable flexible contexts.
856 [dynamic]
857 -XFlexibleInstances
860 Enable flexible instances.
861 [dynamic]
862 -XConstrainedClassMethods
865 Enable constrained class methods.
866 [dynamic]
867 -XMultiParamTypeClasses
870 Enable multi parameter type classes.
871 [dynamic]
872 -XFunctionalDependencies
875 Enable functional dependencies.
876 [dynamic]
877 -XPackageImports
880 Enable package-qualified imports.
881 [dynamic]
882
886 -W enable normal warnings
887 [dynamic]
888 -w disable all warnings
891 [dynamic]
892 -Wall enable almost all warnings (details in )
895 [dynamic]
896 -Werror
899 make warnings fatal
900 [dynamic]
901 -Wwarn make warnings non-fatal
904 [dynamic]
905 -fwarn-unrecognised-pragmas
908 warn about uses of pragmas that GHC doesn't recognise
909 [dynamic]
910 -fwarn-warnings-deprecations
913 warn about uses of functions & types that have warnings or dep‐
914 recated pragmas
915 [dynamic]
916 -fwarn-deprecated-flags
919 warn about uses of commandline flags that are deprecated
920 [dynamic]
921 -fwarn-duplicate-exports
924 warn when an entity is exported multiple times
925 [dynamic]
926 -fwarn-hi-shadowing
929 warn when a .hi file in the current directory shadows a library
930 [dynamic]
931 -fwarn-implicit-prelude
934 warn when the Prelude is implicitly imported
935 [dynamic]
936 -fwarn-incomplete-patterns
939 warn when a pattern match could fail
940 [dynamic]
941 -fwarn-incomplete-record-updates
944 warn when a record update could fail
945 [dynamic]
946 -fwarn-missing-fields
949 warn when fields of a record are uninitialised
950 [dynamic]
951 -fwarn-missing-methods
954 warn when class methods are undefined
955 [dynamic]
956 -fwarn-missing-signatures
959 warn about top-level functions without signatures
960 [dynamic]
961 -fwarn-name-shadowing
964 warn when names are shadowed
965 [dynamic]
966 -fwarn-orphans
969 warn when the module contains orphan instance declarations or
970 rewrite rules
971 [dynamic]
972 -fwarn-overlapping-patterns
975 warn about overlapping patterns
976 [dynamic]
977 -fwarn-simple-patterns
980 warn about lambda-patterns that can fail
981 [dynamic]
982 -fwarn-tabs
985 warn if there are tabs in the source file
986 [dynamic]
987 -fwarn-type-defaults
990 warn when defaulting happens
991 [dynamic]
992 -fwarn-monomorphism-restriction
995 warn when the Monomorphism Restriction is applied
996 [dynamic]
997 -fwarn-unused-binds
1000 warn about bindings that are unused
1001 [dynamic]
1002 -fwarn-unused-imports
1005 warn about unnecessary imports
1006 [dynamic]
1007 -fwarn-unused-matches
1010 warn about variables in patterns that aren't used
1011 [dynamic]
1012 -fwarn-unused-do-bind
1015 warn about do bindings that appear to throw away values of types
1016 other than ()
1017 [dynamic]
1018 -fwarn-wrong-do-bind
1021 warn about do bindings that appear to throw away monadic values
1022 that you should have bound instead
1023 [dynamic]
1024
1028 -O Enable default optimisation (level 1)
1029 [dynamic]
1030 -On Set optimisation level n
1033 [dynamic]
1034
1038 -fcase-merge
1039 Enable case-merging. Implied by -O.
1040 [dynamic]
1041 -fdicts-strict
1044 Make dictionaries strict
1045 [static]
1046 -fmethod-sharing
1049 Share specialisations of overloaded functions (default)
1050 [dynamic]
1051 -fdo-eta-reduction
1054 Enable eta-reduction. Implied by -O.
1055 [dynamic]
1056 -fdo-lambda-eta-expansion
1059 Enable lambda eta-reduction
1060 [dynamic]
1061 -fexcess-precision
1064 Enable excess intermediate precision
1065 [dynamic]
1066 -fignore-asserts
1069 Ignore assertions in the source
1070 [dynamic]
1071 -fignore-interface-pragmas
1074 Ignore pragmas in interface files
1075 [dynamic]
1076 -fomit-interface-pragmas
1079 Don't generate interface pragmas
1080 [dynamic]
1081 -fmax-worker-args
1084 If a worker has that many arguments, none will be unpacked any‐
1085 more (default: 10)
1086 [static]
1087 -fsimplifier-phases
1090 Set the number of phases for the simplifier (default 2). Ignored
1091 with -O0.
1092 [dynamic]
1093 -fmax-simplifier-iterations
1096 Set the max iterations for the simplifier
1097 [dynamic]
1098 -fno-state-hack
1101 Turn off the "state hack" whereby any lambda with a real-world
1102 state token as argument is considered to be single-entry. Hence
1103 OK to inline things inside it.
1104 [static]
1105 -fcse Turn on common sub-expression elimination. Implied by -O.
1108 [dynamic]
1109 -ffull-laziness
1112 Turn on full laziness (floating bindings outwards). Implied by
1113 -O.
1114 [dynamic]
1115 -frewrite-rules
1118 Switch on all rewrite rules (including rules generated by auto‐
1119 matic specialisation of overloaded functions). Implied by -O.
1120 [dynamic]
1121 -fstrictness
1124 Turn on strictness analysis. Implied by -O.
1125 [dynamic]
1126 -fspec-constr
1129 Turn on the SpecConstr transformation. Implied by -O2.
1130 [dynamic]
1131 -fspec-constr-threshold=n
1134 Set the size threshold for the SpecConstr transformation to n
1135 (default: 200)
1136 [static]
1137 -fspec-constr-count=n
1140 Set to n (default: 3) the maximum number of specialisations that
1141 will be created for any one function by the SpecConstr transfor‐
1142 mation
1143 [static]
1144 -fliberate-case
1147 Turn on the liberate-case transformation. Implied by -O2.
1148 [dynamic]
1149 -fstatic-argument-transformation
1152 Turn on the static argument transformation. Implied by -O2.
1153 [dynamic]
1154 -fliberate-case-threshold=n
1157 Set the size threshold for the liberate-case transformation to n
1158 (default: 200)
1159 [static]
1160 -funbox-strict-fields
1163 Flatten strict constructor fields
1164 [dynamic]
1165 -funfolding-creation-threshold
1168 Tweak unfolding settings
1169 [static]
1170 -funfolding-fun-discount
1173 Tweak unfolding settings
1174 [static]
1175 -funfolding-keeness-factor
1178 Tweak unfolding settings
1179 [static]
1180 -funfolding-use-threshold
1183 Tweak unfolding settings
1184 [static]
1185 -fno-pre-inlining
1188 Turn off pre-inlining
1189 [static]
1190 -feager-blackholing
1193 Turn on eager blackholing
1194 [dynamic]
1195
1199 -auto Auto-add _scc_s to all exported functions
1200 [dynamic]
1201 -auto-all
1204 Auto-add _scc_s to all top-level functions
1205 [dynamic]
1206 -caf-all
1209 Auto-add _scc_s to all CAFs
1210 [dynamic]
1211 -prof Turn on profiling
1214 [static]
1215 -ticky Turn on ticky-ticky profiling
1218 [static]
1219
1223 -fhpc Turn on Haskell program coverage instrumentation
1224 [static]
1225 -hpcdir dir
1228 Directory to deposit .mix files during compilation (default is
1229 .hpc)
1230 [dynamic]
1231
1235 -F Enable the use of a pre-processor (set with -pgmF)
1236 [dynamic]
1237
1241 -cpp Run the C pre-processor on Haskell source files
1242 [dynamic]
1243 -Dsymbol=value
1246 Define a symbol in the C pre-processor
1247 [dynamic]
1248 -Usymbol
1251 Undefine a symbol in the C pre-processor
1252 [dynamic]
1253 -Idir Add dir to the directory search list for #include files
1256 [dynamic]
1257
1261 -fasm Use the native code generator
1262 [dynamic]
1263 -fvia-C
1266 Compile via C
1267 [dynamic]
1268 -fno-code
1271 Omit code generation
1272 [dynamic]
1273 -fbyte-code
1276 Generate byte-code
1277 [dynamic]
1278 -fobject-code
1281 Generate object code
1282 [dynamic]
1283
1287 -shared
1288 Generate a shared library (as opposed to an executable)
1289 [dynamic]
1290 -fPIC Generate position-independent code (where available)
1293 [static]
1294 -dynamic
1297 Use dynamic Haskell libraries (if available)
1298 [static]
1299 -dynload
1302 Selects one of a number of modes for finding shared libraries at
1303 runtime.
1304 [static]
1305 -framework name
1308 On Darwin/MacOS X only, link in the framework name. This option
1309 corresponds to the -framework option for Apple's Linker.
1310 [dynamic]
1311 -framework-path name
1314 On Darwin/MacOS X only, add dir to the list of directories
1315 searched for frameworks. This option corresponds to the -F op‐
1316 tion for Apple's Linker.
1317 [dynamic]
1318 -llib Link in library lib
1321 [dynamic]
1322 -Ldir Add dir to the list of directories searched for libraries
1325 [dynamic]
1326 -main-is
1329 Set main module and function
1330 [dynamic]
1331 --mk-dll
1334 DLL-creation mode (Windows only)
1335 [dynamic]
1336 -no-hs-main
1339 Don't assume this program contains main
1340 [dynamic]
1341 -no-link
1344 Omit linking
1345 [dynamic]
1346 -split-objs
1349 Split objects (for libraries)
1350 [dynamic]
1351 -static
1354 Use static Haskell libraries
1355 [static]
1356 -threaded
1359 Use the threaded runtime
1360 [static]
1361 -debug Use the debugging runtime
1364 [static]
1365 -eventlog
1368 Enable runtime event tracing
1369 [static]
1370 -fno-gen-manifest
1373 Do not generate a manifest file (Windows only)
1374 [dynamic]
1375 -fno-embed-manifest
1378 Do not embed the manifest in the executable (Windows only)
1379 [dynamic]
1380 -fno-shared-implib
1383 Don't generate an import library for a DLL (Windows only)
1384 [dynamic]
1385
1389 -pgmL cmd
1390 Use cmd as the literate pre-processor
1391 [dynamic]
1392 -pgmP cmd
1395 Use cmd as the C pre-processor (with -cpp only)
1396 [dynamic]
1397 -pgmc cmd
1400 Use cmd as the C compiler
1401 [dynamic]
1402 -pgmm cmd
1405 Use cmd as the mangler
1406 [dynamic]
1407 -pgms cmd
1410 Use cmd as the splitter
1411 [dynamic]
1412 -pgma cmd
1415 Use cmd as the assembler
1416 [dynamic]
1417 -pgml cmd
1420 Use cmd as the linker
1421 [dynamic]
1422 -pgmdll cmd
1425 Use cmd as the DLL generator
1426 [dynamic]
1427 -pgmF cmd
1430 Use cmd as the pre-processor (with -F only)
1431 [dynamic]
1432 -pgmwindres cmd
1435 Use cmd as the program for embedding manifests on Windows.
1436 [dynamic]
1437
1441 -optL option
1442 pass option to the literate pre-processor
1443 [dynamic]
1444 -optP option
1447 pass option to cpp (with -cpp only)
1448 [dynamic]
1449 -optF option
1452 pass option to the custom pre-processor
1453 [dynamic]
1454 -optc option
1457 pass option to the C compiler
1458 [dynamic]
1459 -optm option
1462 pass option to the mangler
1463 [dynamic]
1464 -opta option
1467 pass option to the assembler
1468 [dynamic]
1469 -optl option
1472 pass option to the linker
1473 [dynamic]
1474 -optdll option
1477 pass option to the DLL generator
1478 [dynamic]
1479 -optwindres option
1482 pass option to windres.
1483 [dynamic]
1484
1488 -monly-[432]-regs
1489 (x86 only) give some registers back to the C compiler
1490 [dynamic]
1491
1495 -fext-core
1496 Generate .hcr external Core files
1497 [dynamic]
1498
1502 -dcore-lint
1503 Turn on internal sanity checking
1504 [dynamic]
1505 -ddump-asm
1508 Dump assembly
1509 [dynamic]
1510 -ddump-bcos
1513 Dump interpreter byte code
1514 [dynamic]
1515 -ddump-cmm
1518 Dump C-- output
1519 [dynamic]
1520 -ddump-cpranal
1523 Dump output from CPR analysis
1524 [dynamic]
1525 -ddump-cse
1528 Dump CSE output
1529 [dynamic]
1530 -ddump-deriv
1533 Dump deriving output
1534 [dynamic]
1535 -ddump-ds
1538 Dump desugarer output
1539 [dynamic]
1540 -ddump-flatC
1543 Dump `flat' C
1544 [dynamic]
1545 -ddump-foreign
1548 Dump foreign export stubs
1549 [dynamic]
1550 -ddump-hpc
1553 Dump after instrumentation for program coverage
1554 [dynamic]
1555 -ddump-inlinings
1558 Dump inlining info
1559 [dynamic]
1560 -ddump-occur-anal
1563 Dump occurrence analysis output
1564 [dynamic]
1565 -ddump-opt-cmm
1568 Dump the results of C-- to C-- optimising passes
1569 [dynamic]
1570 -ddump-parsed
1573 Dump parse tree
1574 [dynamic]
1575 -ddump-prep
1578 Dump prepared core
1579 [dynamic]
1580 -ddump-rn
1583 Dump renamer output
1584 [dynamic]
1585 -ddump-rules
1588 Dump rules
1589 [dynamic]
1590 -ddump-simpl
1593 Dump final simplifier output
1594 [dynamic]
1595 -ddump-simpl-phases
1598 Dump output from each simplifier phase
1599 [dynamic]
1600 -ddump-simpl-iterations
1603 Dump output from each simplifier iteration
1604 [dynamic]
1605 -ddump-spec
1608 Dump specialiser output
1609 [dynamic]
1610 -ddump-splices
1613 Dump TH spliced expressions, and what they evaluate to
1614 [dynamic]
1615 -ddump-stg
1618 Dump final STG
1619 [dynamic]
1620 -ddump-stranal
1623 Dump strictness analyser output
1624 [dynamic]
1625 -ddump-tc
1628 Dump typechecker output
1629 [dynamic]
1630 -ddump-types
1633 Dump type signatures
1634 [dynamic]
1635 -ddump-worker-wrapper
1638 Dump worker-wrapper output
1639 [dynamic]
1640 -ddump-if-trace
1643 Trace interface files
1644 [dynamic]
1645 -ddump-tc-trace
1648 Trace typechecker
1649 [dynamic]
1650 -ddump-rn-trace
1653 Trace renamer
1654 [dynamic]
1655 -ddump-rn-stats
1658 Renamer stats
1659 [dynamic]
1660 -ddump-simpl-stats
1663 Dump simplifier stats
1664 [dynamic]
1665 -dno-debug-output
1668 Suppress unsolicited debugging output
1669 [static]
1670 -dppr-debug
1673 Turn on debug printing (more verbose)
1674 [static]
1675 -dsuppress-uniques
1678 Suppress the printing of uniques in debug output (easier to use
1679 diff.
1680 [static]
1681 -dppr-noprags
1684 Don't output pragma info in dumps
1685 [static]
1686 -dppr-user-length
1689 Set the depth for printing expressions in error msgs
1690 [static]
1691 -dsource-stats
1694 Dump haskell source stats
1695 [dynamic]
1696 -dcmm-lint
1699 C-- pass sanity checking
1700 [dynamic]
1701 -dstg-lint
1704 STG pass sanity checking
1705 [dynamic]
1706 -dstg-stats
1709 Dump STG stats
1710 [dynamic]
1711 -dverbose-core2core
1714 Show output from each core-to-core pass
1715 [dynamic]
1716 -dverbose-stg2stg
1719 Show output from each STG-to-STG pass
1720 [dynamic]
1721 -dshow-passes
1724 Print out each pass name as it happens
1725 [dynamic]
1726 -dfaststring-stats
1729 Show statistics for fast string usage when finished
1730 [dynamic]
1731
1735 -fno-hi-version-check
1736 Don't complain about .hi file mismatches
1737 [static]
1738 -dno-black-holing
1741 Turn off black holing (probably doesn't work)
1742 [static]
1743 -fhistory-size
1746 Set simplification history size
1747 [static]
1748 -funregisterised
1751 Unregisterised compilation (use -unreg instead)
1752 [static]
1753 -fno-asm-mangling
1756 Turn off assembly mangling (use -unreg instead)
1757 [dynamic]
1758
1763 /usr/lib64
1764
1766 Copyright 2002, The University Court of the University of Glasgow.
1767 All rights reserved.
1768
1772 This manual page was generated from the XML documentation of GHC with
1773 blood, sweat, tears and a breaks-if-you-look-at-it-the-wrong-way XSL
1774 stylesheet originally written by Michael Weber <michaelw@debian.org>
1775 for the Debian GNU/Linux system (but may be used by others).
1776Glasgow FP Suite 2002-10-25 GHC(1)