ghc5(1)

Usage

ghc [{option | filename}] ...

Overview

This manual page documents briefly the ghc command. 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 -v -vn --version --numeric-version --print-libdir

Which phases to run

-E -C -S -c

Redirecting output

-hcsuf suffix -hidir dir -hisuf suffix -o filename -odir dir -ohi filename -osuf suffix

Keeping intermediate files

-keep-hc-file -keep-s-file -keep-raw-s-file -keep-tmp-files

Temporary files

-tmpdir

Finding imports

-idir1:dir2:... -i

Interface file options

-ddump-hi -ddump-hi-diffs --show-iface file

Recompilation checking

-no-recomp -recomp

Interactive-mode options

-ignore-dot-ghci -read-dot-ghci

Packages

-package name -package-conf file -package-name name

Language options

-fallow-overlapping-instances -fno-allow-overlapping-instances -fallow-undecidable-instances -fno-allow-undecidable-instances -fgenerics -fno-fgenerics -fglasgow-exts -fno-glasgow-exts -ffi or -fffi -fno-ffi -fwith -fno-with -fignore-asserts -fno-ignore-asserts -fno-implicit-prelude -fno-monomorphism-restriction -firrefutable-tuples -fno-irrefutable-tuples -fcontext-stackn

Warnings

-W -w -w -Wall -w -fwarn-deprecations -fno-warn-deprecations -fwarn-duplicate-exports -fno-warn-duplicate-exports -fwarn-hi-shadowing -fno-warn-hi-shadowing -fwarn-incomplete-patterns -fno-warn-incomplete-patterns -fwarn-misc -fno-warn-misc -fwarn-missing-fields -fno-warn-missing-fields -fwarn-missing-methods -fno-warn-missing-methods -fwarn-missing-signatures -fno-warn-missing-signatures -fwarn-name-shadowing -fno-warn-name-shadowing -fwarn-overlapping-patterns -fno-warn-overlapping-patterns -fwarn-simple-patterns -fno-warn-simple-patterns -fwarn-type-defaults -fno-warn-type-defaults -fwarn-unused-binds -fno-warn-unused-binds -fwarn-unused-imports -fno-warn-unused-imports -fwarn-unused-matches -fno-warn-unused-matches

Optimisation levels

-O -O0 -On -O0

Individual optimisations

-fcase-merge -fno-case-merge -fdicts-strict -fno-dicts-strict -fdo-eta-reduction -fno-do-eta-reduction -fdo-lambda-eta-expansion -fno-do-lambda-eta-expansion -fexcess-precision -fno-excess-precision -ffoldr-build-on -fno-foldr-build-on -fignore-asserts -fno-ignore-asserts -fignore-interface-pragmas -fno-ignore-interface-pragmas -flet-no-escape -fno-let-no-escape -fliberate-case-threshold -fno-liberate-case-threshold -fomit-interface-pragmas -fno-omit-interface-pragmas -fmax-worker-args -fmax-simplifier-iterations -fno-cpr -fno-cse -fno-pre-inlining -fno-strictness -fnumbers-strict -fno-numbers-strict -funbox-strict-fields -fno-unbox-strict-fields -funfolding-creation-threshold -fno-unfolding-creation-threshold -funfolding-fun-discount -fno-unfolding-fun-discount -funfolding-keeness-factor -fno-unfolding-keeness-factor -funfolding-update-in-place -fno-unfolding-update-in-place -funfolding-use-threshold -fno-unfolding-use-threshold -fusagesp -fno-usagesp

Profiling options

-auto -no-auto -auto-all -no-auto-all -auto-dicts -no-auto-dicts -caf-all -no-caf-all -prof -ticky

Parallelism options

-gransim -parallel -smp

C pre-processor options

-cpp -Dsymbol="value" -U -Usymbol -Idir

C compiler options

-#include file

Code generation options

-fasm -fvia-C -fno-code

Linking options

-dynamic -llib -Ldir -package name -framework name -framework-path name -split-objs -static -no-hs-main

Replacing phases

-pgmL cmd -pgmP cmd -pgmc cmd -pgma cmd -pgml cmd -pgmdll cmd -pgmdep cmd -pgmF cmd

Forcing options to particular phases

-optL option -optP option -optc option -opta option -optl option -optdll option -optdep option

Platform-specific options

-mv8 -monly-[32]-regs

External core file options

-fext-core

Compiler debugging options

-dcore-lint -ddump-absC -ddump-asm -ddump-bcos -ddump-cpranal -ddump-cse -ddump-deriv -ddump-ds -ddump-flatC -ddump-foreign -ddump-inlinings -ddump-occur-anal -ddump-parsed -ddump-realC -ddump-rn -ddump-rules -ddump-sat -ddump-simpl -ddump-simpl-iterations -ddump-spec -ddump-stg -ddump-stranal -ddump-tc -ddump-types -ddump-usagesp -ddump-worker-wrapper -ddump-rn-trace -ddump-rn-stats -ddump-stix -ddump-simpl-stats -dppr-debug -dppr-noprags -dppr-user-length -dsource-stats -dstg-lint -dstg-stats -dusagesp-lint -dverbose-core2core -dverbose-stg2stg -unreg

Misc compiler options

-funfold-casms-in-hi-file -femit-extern-decls -fglobalise-toplev-names -fno-hi-version-check -dno-black-holing -fno-method-sharing -fno-prune-decls -fno-prune-tydecls -fhistory-size -funregisterised -fno-asm-mangling

Options

-?: help [static]

-help: help [static]

-v: verbose mode (equivalent to -v3) [dynamic]

-vn: set verbosity level [dynamic]

--version: display GHC version [static]

--numeric-version: display GHC version (numeric only) [static]

--print-libdir: display GHC library directory [static]

Which phases to run

`-E`	Stop after preprocessing (`.hspp` file) [static]
`-C`	Stop after generating C (`.hc` file) [static]
`-S`	Stop after generating assembly (`.s` file) [static]
`-c`	Stop after compiling to object code (`.o` file) [static]

Redirecting output

`-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]

Keeping intermediate files

`-keep-hc-file`	retain intermediate `.hc` files [static]
`-keep-s-file`	retain intermediate `.s` files [static]
`-keep-raw-s-file`	retain intermediate `.raw_s` files [static]
`-keep-tmp-files`	retain all intermediate temporary files [static]

Temporary files

-tmpdir: set the directory for temporary files [static]

Finding imports

`-idir1:dir2:...`	add dir1, dir2, etc. to import path [static]
`-i`	Empty the import directory list [static]

Options

-ddump-hi: Dump the new interface to stdout [dynamic]

-ddump-hi-diffs: Show the differences vs. the old interface [dynamic]

--show-iface file: Read the interface in file and dump it as text to stdout. [static]

Recompilation checking

-no-recomp: Turn off recompilation checking [static]

Options

-ignore-dot-ghci: Disable reading of .ghci files [static]

-read-dot-ghci: Enable reading of .ghci files [static]

Packages

`-package name`	Use package name [static]
`-package-conf file`	Load more packages from file [static]
`-package-name name`	Compile code for package name [static]

Options

-fallow-overlapping-instances: Enable overlapping instances [dynamic]

-fallow-undecidable-instances: Enable undecidable instances [dynamic]

-fgenerics: Enable generics [dynamic]

-fglasgow-exts: Enable most language extensions [dynamic]

-ffi or -fffi: Enable foreign function interface (implied by -fglasgow-exts) [dynamic]

-fwith: Enable deprecated with keyword [dynamic]

-fignore-asserts: Ignore assertions [dynamic]

-fno-implicit-prelude: Don't implicitly import Prelude [dynamic]

-fno-monomorphism-restriction: Disable the monomorphism restriction [dynamic]

-firrefutable-tuples: Make tuple pattern matching irrefutable [dynamic]

-fcontext-stackn: set the limit for context reduction [dynamic]

Warnings

`-W`	enable normal warnings [dynamic]
`-w`	disable all warnings [dynamic]
`-Wall`	enable all warnings [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-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-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) [static]
`-On`	Set optimisation level n [static]

Individual optimisations

-fcase-merge: Enable case-merging [static]

-fdicts-strict: Make dictionaries strict [dynamic]

-fdo-eta-reduction: Enable eta-reduction [static]

-fdo-lambda-eta-expansion: Enable lambda eta-reduction [static]

-fexcess-precision: Enable excess intermediate precision [static]

-ffoldr-build-on: Enable foldr-build optimisation [static]

-fignore-asserts: Ignore assertions in the source [static]

-fignore-interface-pragmas: Ignore pragmas in interface files [static]

-flet-no-escape: Enable let-no-escape optimisation [static]

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

-fomit-interface-pragmas: Don't generate interface pragmas [static]

-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 [static]

-fno-cpr: Turn off CPR analysis [static]

-fno-cse: Turn off common sub-expression [static]

-fno-pre-inlining: Turn off pre-inlining [static]

-fno-strictness: Turn off strictness analysis [static]

-fnumbers-strict: Make numbers strict [dynamic]

-funbox-strict-fields: Flatten strict constructor fields [static]

-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]

-fusagesp: Turn on UsageSP analysis [static]

Options

-auto: Auto-add _scc_s to all exported functions [static]

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

-auto-dicts: Auto-add _scc_s to all dictionaries [static]

-caf-all: Auto-add _scc_s to all CAFs [static]

-prof: Turn on profiling [static]

-ticky: Turn on ticky-ticky profiling [static]

Options

-gransim: Enable GRANSIM [static]

-parallel: Enable Parallel Haskell [static]

-smp: Enable SMP support [static]

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 [static]

Options

-#include file: Include file when compiling the .hc file [dynamic]

Options

-fasm: Use the native code generator [dynamic]

-fvia-C: Compile via C [dynamic]

-fno-code: Omit code generation [static]

Options

-dynamic: Use dynamic Haskell libraries (if available) [static]

-llib: Link in library lib [static]

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

-package name: Link in package name [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]

-split-objs: Split objects (for libraries) [static]

-static: Use static Haskell libraries [static]

-no-hs-main: Don't asssume this program contains main [static]

Replacing phases

`-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]

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]
`-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]

Options

-mv8: (SPARC only) enable version 8 support [static]

-monly-[32]-regs: (x86 only) give some registers back to the C compiler [dynamic]

Options

-fext-core: Generate .hcr external Core files [static]

Options

-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 foreign 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]

Options

-funfold-casms-in-hi-file: Allow casms in unfoldings [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 .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]

-fno-prune-tydecls: Renamer: don't prune type 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]

Files

/usr/lib/ghc-5.04.3