GHC - the Glasgow Haskell Compiler

ghc [option|filename]...

ghci [option|filename]...

ghc6 [option|filename]...

ghci6 [option|filename]...

This manual page documents briefly the ghc and ghci commands. Extensive documentation is available in various other formats including DVI, PostScript and HTML; see below.

Each of GHC's command line options is classified as either static or dynamic. A static flag may only be specified on the command line, whereas a dynamic flag may also be given in an CROPTIONS pragma in a source file or set from the GHCi command-line with CR:set.

As a rule of thumb, all the language options are dynamic, as are the warning options and the debugging options.

The rest are static, with the notable exceptions of -v, -cpp, -fasm, -fvia-C, and -#include. The OPTIONS sections lists the status of each flag.

Common suffixes of file names for Haskell are:

.hs

Haskell source code; preprocess, compile

.lhs

literate Haskell source; unlit, preprocess, compile

.hi

Interface file; contains information about exported symbols

.hc

intermediate C files

.x_o

way x object files; common ways are: p, u, s

.x_hi

way x interface files

Help and verbosity options

Which phases to run

Alternative modes of operation

Redirecting output

Keeping intermediate files

Temporary files

Finding imports

Interface file options

Recompilation checking

Interactive-mode options

Packages

Language options

Warnings

Optimisation levels

Individual optimisations

Profiling options

Parallelism options

C pre-processor options

C compiler options

Code generation options

Linking options

Replacing phases

Forcing options to particular phases

Platform-specific options

External core file options

Compiler debugging options

Misc compiler options

-?

help [static]

-help

help [static]

-v

verbose mode (equivalent to -v3) [dynamic]

-vn

set verbosity level [dynamic]

-V

display GHC version [static]

--version

display GHC version [static]

--numeric-version

display GHC version (numeric only) [static]

--print-libdir

display GHC library directory [static]

-ferror-spans

output full span in error messages [static]

-E

Stop after preprocessing (CR.hspp file) [static]

-C

Stop after generating C (CR.hc file) [static]

-S

Stop after generating assembly (CR.s file) [static]

-c

Stop after compiling to object code (CR.o file) [static]

--interactive

Interactive mode - normally used by just running ghci [static]

--make

Build a multi-module Haskell program, automatically figuring out dependencies. Likely to be much easier, and faster, than using make. [static]

-e expr

Evaluate expr [static]

-M

Generate dependency information suitable for use in a Makefile. [static]

--mk-dll

DLL-creation mode (Windows only) [static]

-hcsuf suffix

set the suffix to use for intermediate C files [static]

-hidir dir

set directory for interface files [static]

-hisuf suffix

set the suffix to use for interface files [static]

-o filename

set output filename [static]

-odir dir

set output directory [static]

-ohi filename

set the filename in which to put the interface [static]

-osuf suffix

set the output file suffix [static]

-keep-hc-file

retain intermediate CR.hc files [static]

-keep-s-file

retain intermediate CR.s files [static]

-keep-raw-s-file

retain intermediate CR.raw_s files [static]

-keep-tmp-files

retain all intermediate temporary files [static]

-tmpdir

set the directory for temporary files [static]

-idir1:dir2:...

add dir, dir2, etc. to import path [static]

-i

Empty the import directory list [static]

-ddump-hi

Dump the new interface to stdout [dynamic]

-ddump-hi-diffs

Show the differences vs. the old interface [dynamic]

-ddump-minimal-imports

Dump a minimal set of imports [dynamic]

--show-iface file

Read the interface in file and dump it as text to CRstdout. [static]

-no-recomp

Turn off recompilation checking; implied by any -ddump-X option [dynamic]

-ignore-dot-ghci

Disable reading of .ghci files [static]

-read-dot-ghci

Enable reading of .ghci files [static]

-package P

Expose package P [static]

-hide-all-packages

Hide all packages by default [static]

-hide-package name

Hide package P [static]

-ignore-package name

Ignore package P [static]

-package-conf file

Load more packages from file [static]

-no-user-package-conf

Don't load the user's package config file. [static]

-fallow-overlapping-instances

Enable overlapping instances [dynamic]

-fallow-undecidable-instances

Enable undecidable instances [dynamic]

-fallow-incoherent-instances

Enable incoherent instances [dynamic]

-farrows

Enable arrow notation extension [dynamic]

-fcontext-stackn

set the limit for context reduction [static]

-ffi or -fffi

Enable foreign function interface (implied by -fglasgow-exts) [dynamic]

-fgenerics

Enable generics [dynamic]

-fglasgow-exts

Enable most language extensions [dynamic]

-fignore-asserts

Ignore assertions [dynamic]

-fimplicit-params

Enable Implicit Parameters. Implied by -fglasgow-exts. [dynamic]

-firrefutable-tuples

Make tuple pattern matching irrefutable [dynamic]

-fno-implicit-prelude

Don't implicitly CRimport Prelude [dynamic]

-fno-monomorphism-restriction

Disable the monomorphism restriction [dynamic]

-fscoped-type-variables

Enable lexically-scoped type variables. Implied by -fglasgow-exts. [dynamic]

-fth

Enable Template Haskell. Implied by -fglasgow-exts. [dynamic]

-W

enable normal warnings [dynamic]

-w

disable all warnings [dynamic]

-Wall

enable all warnings [dynamic]

-Werror

make warnings fatal [dynamic]

-fwarn-deprecations

warn about uses of functions & types that are deprecated [dynamic]

-fwarn-duplicate-exports

warn when an entity is exported multiple times [dynamic]

-fwarn-hi-shadowing

warn when a CR.hi file in the current directory shadows a library [dynamic]

-fwarn-incomplete-patterns

warn when a pattern match could fail [dynamic]

-fwarn-incomplete-record-updates

warn when a record update could fail [dynamic]

-fwarn-misc

enable miscellaneous warnings [dynamic]

-fwarn-missing-fields

warn when fields of a record are uninitialised [dynamic]

-fwarn-missing-methods

warn when class methods are undefined [dynamic]

-fwarn-missing-signatures

warn about top-level functions without signatures [dynamic]

-fwarn-name-shadowing

warn when names are shadowed [dynamic]

-fwarn-oprhans

warn when the module contains "orphan" instance declarations or rewrite rules [dynamic]

-fwarn-overlapping-patterns

warn about overlapping patterns [dynamic]

-fwarn-simple-patterns

warn about lambda-patterns that can fail [dynamic]

-fwarn-type-defaults

warn when defaulting happens [dynamic]

-fwarn-unused-binds

warn about bindings that are unused [dynamic]

-fwarn-unused-imports

warn about unnecessary imports [dynamic]

-fwarn-unused-matches

warn about variables in patterns that aren't used [dynamic]

-O

Enable default optimisation (level 1) [dynamic]

-On

Set optimisation level n [dynamic]

-fcase-merge

Enable case-merging [dynamic]

-fdicts-strict

Make dictionaries strict [static]

-fdo-eta-reduction

Enable eta-reduction [dynamic]

-fdo-lambda-eta-expansion

Enable lambda eta-reduction [dynamic]

-fexcess-precision

Enable excess intermediate precision [static]

-frules-off

Switch off all rewrite rules (including rules generated by automatic specialisation of overloaded functions) [static]

-fignore-asserts

Ignore assertions in the source [static]

-fignore-interface-pragmas

Ignore pragmas in interface files [static]

-fliberate-case-threshold

Tweak the liberate-case optimisation (default: 10) [static]

-fomit-interface-pragmas

Don't generate interface pragmas [dynamic]

-fmax-worker-args

If a worker has that many arguments, none will be unpacked anymore (default: 10) [static]

-fmax-simplifier-iterations

Set the max iterations for the simplifier [dynamic]

-fno-state-hack

Turn off the "state hack" whereby any lambda with a real-world state token as argument is considered to be single-entry. Hence OK to inline things inside it. [static]

-fno-cse

Turn off common sub-expression [dynamic]

-fno-full-laziness

Turn off full laziness (floating bindings outwards). [dynamic]

-fno-pre-inlining

Turn off pre-inlining [static]

-fno-strictness

Turn off strictness analysis [dynamic]

-funbox-strict-fields

Flatten strict constructor fields [dynamic]

-funfolding-creation-threshold

Tweak unfolding settings [static]

-funfolding-fun-discount

Tweak unfolding settings [static]

-funfolding-keeness-factor

Tweak unfolding settings [static]

-funfolding-update-in-place

Tweak unfolding settings [static]

-funfolding-use-threshold

Tweak unfolding settings [static]

-auto

Auto-add CR_scc_s to all exported functions [static]

-auto-all

Auto-add CR_scc_s to all top-level functions [static]

-auto-dicts

Auto-add CR_scc_s to all dictionaries [static]

-caf-all

Auto-add CR_scc_s to all CAFs [static]

-prof

Turn on profiling [static]

-ticky

Turn on ticky-ticky profiling [static]

-gransim

Enable GRANSIM [static]

-parallel

Enable Parallel Haskell [static]

-smp

Enable SMP support [static]

-cpp

Run the C pre-processor on Haskell source files [dynamic]

-Dsymbol=value

Define a symbol in the C pre-processor [dynamic]

-Usymbol

Undefine a symbol in the C pre-processor [dynamic]

-Idir

Add dir to the directory search list for CR#include files [static]

-#include file

Include file when compiling the .hc file [dynamic]

-fasm

Use the native code generator [dynamic]

-fvia-C

Compile via C [dynamic]

-fno-code

Omit code generation [static]

-dynamic

Use dynamic Haskell libraries (if available) [static]

-framework name

On Darwin/MacOS X only, link in the framework name. This option corresponds to the -framework option for Apple's Linker. [static]

-framework-path name

On Darwin/MacOS X only, add dir to the list of directories searched for frameworks. This option corresponds to the -F option for Apple's Linker. [static]

-llib

Link in library lib [static]

-Ldir

Add dir to the list of directories searched for libraries [static]

-main-is

Set main function [static]

-no-hs-main

Don't assume this program contains CRmain [static]

-no-link

Omit linking [static]

-package name

Link in package name [static]

-split-objs

Split objects (for libraries) [static]

-static

Use static Haskell libraries [static]

-threaded

Use the threaded runtime [static]

-debug

Use the debugging runtime [static]

-pgmL cmd

Use cmd as the literate pre-processor [static]

-pgmP cmd

Use cmd as the C pre-processor (with -cpp only) [static]

-pgmc cmd

Use cmd as the C compiler [static]

-pgma cmd

Use cmd as the assembler [static]

-pgml cmd

Use cmd as the linker [static]

-pgmdll cmd

Use cmd as the DLL generator [static]

-pgmdep cmd

Use cmd as the dependency generator [static]

-pgmF cmd

Use cmd as the pre-processor (with -F only) [static]

-optL option

pass option to the literate pre-processor [dynamic]

-optP option

pass option to cpp (with -cpp only) [dynamic]

-optF option

pass option to the custom pre-processor [dynamic]

-optc option

pass option to the C compiler [dynamic]

-opta option

pass option to the assembler [dynamic]

-optl option

pass option to the linker [static]

-optdll option

pass option to the DLL generator [static]

-optdep option

pass option to the dependency generator [static]

-mv8

(SPARC only) enable version 8 support [static]

-monly-[32]-regs

(x86 only) give some registers back to the C compiler [dynamic]

-fext-core

Generate .hcr external Core files [static]

-dcore-lint

Turn on internal sanity checking [dynamic]

-ddump-absC

Dump abstract C [dynamic]

-ddump-asm

Dump assembly [dynamic]

-ddump-bcos

Dump interpreter byte code [dynamic]

-ddump-cpranal

Dump output from CPR analysis [dynamic]

-ddump-cse

Dump CSE output [dynamic]

-ddump-deriv

Dump deriving output [dynamic]

-ddump-ds

Dump desugarer output [dynamic]

-ddump-flatC

Dump `flat' C [dynamic]

-ddump-foreign

Dump CRforeign export stubs [dynamic]

-ddump-inlinings

Dump inlining info [dynamic]

-ddump-occur-anal

Dump occurrence analysis output [dynamic]

-ddump-parsed

Dump parse tree [dynamic]

-ddump-realC

Dump `real' C [dynamic]

-ddump-rn

Dump renamer output [dynamic]

-ddump-rules

Dump rules [dynamic]

-ddump-sat

Dump saturated output [dynamic]

-ddump-simpl

Dump final simplifier output [dynamic]

-ddump-simpl-iterations

Dump output from each simplifier iteration [dynamic]

-ddump-spec

Dump specialiser output [dynamic]

-ddump-stg

Dump final STG [dynamic]

-ddump-stranal

Dump strictness analyser output [dynamic]

-ddump-tc

Dump typechecker output [dynamic]

-ddump-types

Dump type signatures [dynamic]

-ddump-usagesp

Dump UsageSP analysis output [dynamic]

-ddump-worker-wrapper

Dump worker-wrapper output [dynamic]

-ddump-rn-trace

Trace renamer [dynamic]

-ddump-rn-stats

Renamer stats [dynamic]

-ddump-stix

Native code generator intermediate form [dynamic]

-ddump-simpl-stats

Dump simplifier stats [dynamic]

-dppr-debug

Turn on debug printing (more verbose) [static]

-dppr-noprags

Don't output pragma info in dumps [static]

-dppr-user-length

Set the depth for printing expressions in error msgs [static]

-dsource-stats

Dump haskell source stats [dynamic]

-dstg-lint

STG pass sanity checking [dynamic]

-dstg-stats

Dump STG stats [dynamic]

-dusagesp-lint

UsageSP sanity checker [dynamic]

-dverbose-core2core

Show output from each core-to-core pass [dynamic]

-dverbose-stg2stg

Show output from each STG-to-STG pass [dynamic]

-unreg

Enable unregisterised compilation [static]

-femit-extern-decls

??? [static]

-fglobalise-toplev-names

Make all top-level names global (for -split-objs) [static]

-fno-hi-version-check

Don't complain about CR.hi file mismatches [static]

-dno-black-holing

Turn off black holing (probably doesn't work) [static]

-fno-method-sharing

Don't share specialisations of overloaded functions [static]

-fno-prune-decls

Renamer: don't prune declarations [static]

-fhistory-size

Set simplification history size [static]

-funregisterised

Unregisterised compilation (use -unreg instead) [static]

-fno-asm-mangling

Turn off assembly mangling (use -unreg instead) [static]

/usr/lib/ghc-6.4.1/

Copyright 2002, The University Court of the University of Glasgow.

All rights reserved.

This manual page was generated from the XML documentation of GHC with blood, sweat, tears and a breaks-if-you-look-at-it-the-wrong-way XSL stylesheet by Michael Weber <michaelw@debian.org> for the Debian GNU/Linux system (but may be used by others).