ghci-6.6(1)

NAME

GHC - the Glasgow Haskell Compiler

SYNOPSIS

ghc [option|filename]...
ghci [option|filename]...
ghc6 [option|filename]...
ghci6 [option|filename]...

DESCRIPTION

This manual page documents briefly the ghc and ghci commands. Note that ghci is not yet available on all architectures. 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 OPTIONS pragma in a source file or set from the GHCi command-line with :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

OPTIONS

HELP AND VERBOSITY OPTIONS

-?

help [mode]

-help

help [mode]

-n

do a dry run [dynamic]

-v

verbose mode (equivalent to -v3) [dynamic]

-vn

set verbosity level [dynamic]

-V

display GHC version [mode]

--version

display GHC version [mode]

--numeric-version

display GHC version (numeric only) [mode]

--print-libdir

display GHC library directory [mode]

-ferror-spans

output full span in error messages [static]

-Hsize

Set the minimum heap size to size [static]

-Rghc-timing

Summarise timing stats for GHC (same as +RTS -tstderr) [static]

WHICH PHASES TO RUN

-E

Stop after preprocessing (.hspp file) [mode]

-C

Stop after generating C (.hc file) [mode]

-S

Stop after generating assembly (.s file) [mode]

-c

Do not link [dynamic]

-x suffix

Override default behaviour for source files [static]

ALTERNATIVE MODES OF OPERATION

--interactive

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

--make

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

-e expr

Evaluate expr [mode]

-M

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

REDIRECTING OUTPUT

-hcsuf suffix

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

-hidir dir

set directory for interface files [dynamic]

-hisuf suffix

set the suffix to use for interface files [dynamic]

-o filename

set output filename [dynamic]

-odir dir

set output directory [dynamic]

-ohi filename

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

-osuf suffix

set the output file suffix [dynamic]

-stubdir dir

redirect FFi stub files [dynamic]

KEEPING INTERMEDIATE FILES

-keep-hc-file

retain intermediate .hc files [dynamic]

-keep-s-file

retain intermediate .s files [dynamic]

-keep-raw-s-file

retain intermediate .raw_s files [dynamic]

-keep-tmp-files

retain all intermediate temporary files [dynamic]

TEMPORARY FILES

-tmpdir

set the directory for temporary files [dynamic]

FINDING IMPORTS

-idir1:dir2:...

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

-i

Empty the import directory list [dynamic]

INTERFACE FILE OPTIONS

-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 stdout. [mode]

RECOMPILATION CHECKING

-fforce-recomp

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

INTERACTIVE-MODE OPTIONS

-ignore-dot-ghci

Disable reading of .ghci files [static]

-read-dot-ghci

Enable reading of .ghci files [static]

PACKAGES

-package-name P

Compile to be part of package P [dynamic]

-package P

Expose package P [dynamic]

-hide-all-packages

Hide all packages by default [static]

-hide-package name

Hide package P [dynamic]

-ignore-package name

Ignore package P [dynamic]

-package-conf file

Load more packages from file [dynamic]

-no-user-package-conf

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

LANGUAGE OPTIONS

-fallow-overlapping-instances

Enable overlapping instances [dynamic]

-fallow-incoherent-instances

Enable incoherent instances. Implies -fallow-overlapping-instances [dynamic]

-fallow-undecidable-instances

Enable undecidable instances [dynamic]

-fcontext-stack=Nn

set the limit for context reduction [dynamic]

-farrows

Enable arrow notation extension [dynamic]

-ffi or -fffi

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

-fgenerics

Enable generic classes [dynamic]

-fglasgow-exts

Enable most language extensions [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 import Prelude [dynamic]

-fno-monomorphism-restriction

Disable the monomorphism restriction [dynamic]

-fno-mono-pat-binds

Make pattern bindings polymorphic [dynamic]

-fextended-default-rules

Use GHCi's extended default rules in a normal module [dynamic]

-fscoped-type-variables

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

-fth

Enable Template Haskell. No longer implied by -fglasgow-exts. [dynamic]

-fbang-patterns

Enable bang patterns. [dynamic]

WARNINGS

-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 .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-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-orphans

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]

OPTIMISATION LEVELS

-O

Enable default optimisation (level 1) [dynamic]

-On

Set optimisation level n [dynamic]

INDIVIDUAL OPTIMISATIONS

-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 [dynamic]

-frules-off

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

-fignore-asserts

Ignore assertions in the source [dynamic]

-fignore-interface-pragmas

Ignore pragmas in interface files [dynamic]

-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]

PROFILING OPTIONS

-auto

Auto-add _scc_s to all exported functions [static]

-auto-all

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

-caf-all

Auto-add _scc_s to all CAFs [static]

-prof

Turn on profiling [static]

-ticky

Turn on ticky-ticky profiling [static]

HASKELL PRE-PROCESSOR OPTIONS

-F

Enable the use of a pre-processor (set with -pgmF) [dynamic]

C PRE-PROCESSOR OPTIONS

-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 #include files [dynamic]

C COMPILER OPTIONS

-#include file

Include file when compiling the .hc file [dynamic]

CODE GENERATION OPTIONS

-fasm

Use the native code generator [dynamic]

-fvia-C

Compile via C [dynamic]

-fno-code

Omit code generation [mode]

LINKING OPTIONS

-fPIC

Generate position-independent code (where available) [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. [dynamic]

-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. [dynamic]

-llib

Link in library lib [dynamic]

-Ldir

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

-main-is

Set main function [dynamic]

--mk-dll

DLL-creation mode (Windows only) [dynamic]

-no-hs-main

Don't assume this program contains main [dynamic]

-no-link

Omit linking [dynamic]

-split-objs

Split objects (for libraries) [dynamic]

-static

Use static Haskell libraries [static]

-threaded

Use the threaded runtime [static]

-debug

Use the debugging runtime [static]

REPLACING PHASES

-pgmL cmd

Use cmd as the literate pre-processor [dynamic]

-pgmP cmd

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

-pgmc cmd

Use cmd as the C compiler [dynamic]

-pgmm cmd

Use cmd as the mangler [dynamic]

-pgms cmd

Use cmd as the splitter [dynamic]

-pgma cmd

Use cmd as the assembler [dynamic]

-pgml cmd

Use cmd as the linker [dynamic]

-pgmdll cmd

Use cmd as the DLL generator [dynamic]

-pgmF cmd

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

FORCING OPTIONS TO PARTICULAR PHASES

-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]

-optm option

pass option to the mangler [dynamic]

-opta option

pass option to the assembler [dynamic]

-optl option

pass option to the linker [dynamic]

-optdll option

pass option to the DLL generator [dynamic]

-optdep option

pass option to the dependency generator [dynamic]

PLATFORM-SPECIFIC OPTIONS

-monly-[432]-regs

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

EXTERNAL CORE FILE OPTIONS

-fext-core

Generate .hcr external Core files [static]

COMPILER DEBUGGING OPTIONS

-dcore-lint

Turn on internal sanity checking [dynamic]

-ddump-asm

Dump assembly [dynamic]

-ddump-bcos

Dump interpreter byte code [dynamic]

-ddump-cmm

Dump C-- output [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 foreign export stubs [dynamic]

-ddump-inlinings

Dump inlining info [dynamic]

-ddump-occur-anal

Dump occurrence analysis output [dynamic]

-ddump-opt-cmm

Dump the results of C-- to C-- optimising passes [dynamic]

-ddump-parsed

Dump parse tree [dynamic]

-ddump-prep

Dump prepared core [dynamic]

-ddump-rn

Dump renamer output [dynamic]

-ddump-rules

Dump rules [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-splices

Dump TH splided expressions, and what they evaluate to [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-worker-wrapper

Dump worker-wrapper output [dynamic]

-ddump-if-trace

Trace interface files [dynamic]

-ddump-tc-trace

Trace typechecker [dynamic]

-ddump-rn-trace

Trace renamer [dynamic]

-ddump-rn-stats

Renamer stats [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]

-dcmm-lint

C-- pass sanity checking [dynamic]

-dstg-lint

STG pass sanity checking [dynamic]

-dstg-stats

Dump STG stats [dynamic]

-dverbose-core2core

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

-dverbose-stg2stg

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

-dshow-passes

Print out each pass name as it happens [dynamic]

-dfaststring-stats

Show statistics for fast string usage when finished [dynamic]

-unreg

Enable unregisterised compilation [static]

MISC COMPILER OPTIONS

-fno-hi-version-check

Don't complain about .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]

-fhistory-size

Set simplification history size [static]

-funregisterised

Unregisterised compilation (use -unreg instead) [static]

-fno-asm-mangling

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

-fno-print-bind-result

Turn off printing of binding results in GHCi [dynamic]

FILES

/usr/lib/ghc-6.6/

COPYRIGHT

Copyright 2002, The University Court of the University of Glasgow.
All rights reserved.

AUTHOR

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 <[email protected]> for the Debian GNU/Linux system (but may be used by others).