4.17. Flag reference
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## 4.17. Flag reference

This section is a quick-reference for GHC's command-line flags. For each flag, we also list its static/dynamic status (see Section 4.2, “Static, Dynamic, and Mode options”), and the flag's opposite (if available).

### 4.17.1. Help and verbosity options

Section 4.5, “Help and verbosity options”

Flag | Description | Static/Dynamic | Reverse
--- | --- | --- | ---
`-?` | help | mode | -
`-help` | help | mode | -
`-n` | do a dry run | dynamic | -
`-v` | verbose mode (equivalent to `-v3`) | dynamic | -
`-v` `n` | set verbosity level | dynamic | -
`-V` | display GHC version | mode | -
`––supported-languages` | display the supported language extensions | mode | -
`––info` | display information about the compiler | 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 | -
`-H` `size` | Set the minimum heap size to `size` | static | -
`-Rghc-timing` | Summarise timing stats for GHC (same as `+RTS -tstderr`) | static | -

### 4.17.2. Which phases to run

Section 4.4.3, “Batch compiler mode”

Flag | Description | Static/Dynamic | Reverse
--- | --- | --- | ---
`-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 | -

### 4.17.3. Alternative modes of operation

Section 4.4, “Modes of operation”

Flag | Description | Static/Dynamic | Reverse
--- | --- | --- | ---
`--interactive` | Interactive mode - normally used by just running ghci; see Chapter 2, Using GHCi for details. | mode | -
`--make` | Build a multi-module Haskell program, automatically figuring out dependencies. Likely to be much easier, and faster, than using make; see Section 4.4.1, “Using ghc `––make`” for details.. | mode | -
`-e `expr`` | Evaluate `expr`; see Section 4.4.2, “Expression evaluation mode” for details. | mode | -
`-M` | Generate dependency information suitable for use in a `Makefile`; see Section 4.6.11, “Dependency generation” for details. | mode | -

### 4.17.4. Redirecting output

Section 4.6.4, “Redirecting the compilation output(s)”

Flag | Description | Static/Dynamic | Reverse
--- | --- | --- | ---
`-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 directory for object files | 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 | -
`-outputdir` `dir` | set output directory | dynamic | -

### 4.17.5. Keeping intermediate files

Section 4.6.5, “Keeping Intermediate Files”

Flag | Description | Static/Dynamic | Reverse
--- | --- | --- | ---
`-keep-hc-file` or `-keep-hc-files` | retain intermediate `.hc` files | dynamic | -
`-keep-s-file` or `-keep-s-files` | retain intermediate `.s` files | dynamic | -
`-keep-raw-s-file` or `-keep-raw-s-files` | retain intermediate `.raw_s` files | dynamic | -
`-keep-tmp-files` | retain all intermediate temporary files | dynamic | -

### 4.17.6. Temporary files

Section 4.6.6, “Redirecting temporary files”

Flag | Description | Static/Dynamic | Reverse
--- | --- | --- | ---
`-tmpdir` | set the directory for temporary files | dynamic | -

### 4.17.7. Finding imports

Section 4.6.3, “The search path”

Flag | Description | Static/Dynamic | Reverse
--- | --- | --- | ---
`-i` `dir1`:`dir2`:... | add `dir`, `dir2`, etc. to import path | static/`:set` | -
`-i` | Empty the import directory list | static/`:set` | -

### 4.17.8. Interface file options

Section 4.6.7, “Other options related to interface files”

Flag | Description | Static/Dynamic | Reverse
--- | --- | --- | ---
`-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` | See Section 4.4, “Modes of operation”. |  |

### 4.17.9. Recompilation checking

Section 4.6.8, “The recompilation checker”

Flag | Description | Static/Dynamic | Reverse
--- | --- | --- | ---
`-fforce-recomp` | Turn off recompilation checking; implied by any `-ddump-X` option | dynamic | `-fno-force-recomp`

### 4.17.10. Interactive-mode options

Section 2.9, “The `.ghci` file”

Flag | Description | Static/Dynamic | Reverse
--- | --- | --- | ---
`-ignore-dot-ghci` | Disable reading of `.ghci` files | static | -
`-read-dot-ghci` | Enable reading of `.ghci` files | static | -
`-fbreak-on-exception` | Break on any exception thrown | dynamic | `-fno-break-on-exception`
`-fbreak-on-error` | Break on uncaught exceptions and errors | dynamic | `-fno-break-on-error`
`-fprint-evld-with-show` | Enable usage of Show instances in `:print` | dynamic | `-fno-print-evld-with-show`
`-fprint-bind-result` | Turn on printing of binding results in GHCi | dynamic | `-fno-print-bind-result`
`-fno-print-bind-contents` | Turn off printing of binding contents in GHCi | dynamic | -
`-fno-implicit-import-qualified` | Turn off implicit qualified import of everything in GHCi | dynamic | -

### 4.17.11. Packages

Section 4.8, “ Packages ”

Flag | Description | Static/Dynamic | Reverse
--- | --- | --- | ---
`-package-name` `P` | Compile to be part of package `P` | dynamic | -
`-package` `P` | Expose package `P` | static/`:set` | -
`-hide-all-packages` | Hide all packages by default | static | -
`-hide-package` `name` | Hide package `P` | static/`:set` | -
`-ignore-package` `name` | Ignore package `P` | static/`:set` | -
`-package-conf` `file` | Load more packages from `file` | static | -
`-no-user-package-conf` | Don't load the user's package config file. | static | -

### 4.17.12. Language options

Section 7.1, “Language options”

Flag | Description | Static/Dynamic | Reverse
--- | --- | --- | ---
`-fglasgow-exts` | Enable most language extensions | dynamic | `-fno-glasgow-exts`
`-XOverlappingInstances` | Enable overlapping instances | dynamic | `-XNoOverlappingInstances`
`-XIncoherentInstances` | Enable incoherent instances. Implies `-XOverlappingInstances` | dynamic | `-XNoIncoherentInstances`
`-XUndecidableInstances` | Enable undecidable instances | dynamic | `-XNoUndecidableInstances`
`-fcontext-stack=N` `n` | set the limit for context reduction. Default is 20. | dynamic |
`-XArrows` | Enable arrow notation extension | dynamic | `-XNoArrows`
`-XDisambiguateRecordFields` | Enable record field disambiguation | dynamic | `-XNoDisambiguateRecordFields`
`-XForeignFunctionInterface` | Enable foreign function interface (implied by `-fglasgow-exts`) | dynamic | `-XNoForeignFunctionInterface`
`-XGenerics` | Enable generic classes | dynamic | `-XNoGenerics`
`-XImplicitParams` | Enable Implicit Parameters. Implied by `-fglasgow-exts`. | dynamic | `-XNoImplicitParams`
`-firrefutable-tuples` | Make tuple pattern matching irrefutable | dynamic | `-fno-irrefutable-tuples`
`-XNoImplicitPrelude` | Don't implicitly `import Prelude` | dynamic | `-XImplicitPrelude`
`-XNoMonomorphismRestriction` | Disable the monomorphism restriction | dynamic | `-XMonomorphismRrestriction`
`-XNoMonoPatBinds` | Make pattern bindings polymorphic | dynamic | `-XMonoPatBinds`
`-XRelaxedPolyRec` | Relaxed checking for mutually-recursive polymorphic functions | dynamic | `-XNoRelaxedPolyRec`
`-XExtendedDefaultRules` | Use GHCi's extended default rules in a normal module | dynamic | `-XNoExtendedDefaultRules`
`-XOverloadedStrings` | Enable overloaded string literals. | dynamic | `-XNoOverloadedStrings`
`-XGADTs` | Enable generalised algebraic data types. | dynamic | `-XNoGADTs`
`-XTypeFamilies` | Enable type families. | dynamic | `-XNoTypeFamilies`
`-XScopedTypeVariables` | Enable lexically-scoped type variables. Implied by `-fglasgow-exts`. | dynamic | `-XNoScopedTypeVariables`
`-XTemplateHaskell` | Enable Template Haskell. No longer implied by `-fglasgow-exts`. | dynamic | `-XNoTemplateHaskell`
`-XQuasiQuotes` | Enable quasiquotation. | dynamic | `-XNoQuasiQuotes`
`-XBangPatterns` | Enable bang patterns. | dynamic | `-XNoBangPatterns`
`-XCPP` | Enable the C preprocessor. | dynamic | `-XNoCPP`
`-XPatternGuards` | Enable pattern guards. | dynamic | `-XNoPatternGuards`
`-XViewPatterns` | Enable view patterns. | dynamic | `-XNoViewPatterns`
`-XUnicodeSyntax` | Enable unicode syntax. | dynamic | `-XNoUnicodeSyntax`
`-XMagicHash` | Allow "#" as a postfix modifier on identifiers. | dynamic | `-XNoMagicHash`
`-XNewQualifiedOperators` | Enable new qualified operator syntax | dynamic | `-XNoNewQualifiedOperators`
`-XPolymorphicComponents` | Enable polymorphic components for data constructors. | dynamic | `-XNoPolymorphicComponents`
`-XRank2Types` | Enable rank-2 types. | dynamic | `-XNoRank2Types`
`-XRankNTypes` | Enable rank-N types. | dynamic | `-XNoRankNTypes`
`-XImpredicativeTypes` | Enable impredicative types. | dynamic | `-XNoImpredicativeTypes`
`-XExistentialQuantification` | Enable existential quantification. | dynamic | `-XNoExistentialQuantification`
`-XKindSignatures` | Enable kind signatures. | dynamic | `-XNoKindSignatures`
`-XEmptyDataDecls` | Enable empty data declarations. | dynamic | `-XNoEmptyDataDecls`
`-XParallelListComp` | Enable parallel list comprehensions. | dynamic | `-XNoParallelListComp`
`-XTransformListComp` | Enable transform list comprehensions. | dynamic | `-XNoTransformListComp`
`-XUnliftedFFITypes` | Enable unlifted FFI types. | dynamic | `-XNoUnliftedFFITypes`
`-XLiberalTypeSynonyms` | Enable liberalised type synonyms. | dynamic | `-XNoLiberalTypeSynonyms`
`-XTypeOperators` | Enable type operators. | dynamic | `-XNoTypeOperators`
`-XRecursiveDo` | Enable recursive do (mdo) notation. | dynamic | `-XNoRecursiveDo`
`-XPArr` | Enable parallel arrays. | dynamic | `-XNoPArr`
`-XRecordWildCards` | Enable record wildcards. | dynamic | `-XNoRecordWildCards`
`-XNamedFieldPuns` | Enable record puns. | dynamic | `-XNoNamedFieldPuns`
`-XDisambiguateRecordFields` | Enable record field disambiguation. | dynamic | `-XNoDisambiguateRecordFields`
`-XUnboxedTuples` | Enable unboxed tuples. | dynamic | `-XNoUnboxedTuples`
`-XStandaloneDeriving` | Enable standalone deriving. | dynamic | `-XNoStandaloneDeriving`
`-XDeriveDataTypeable` | Enable deriving for the Data and Typeable classes. | dynamic | `-XNoDeriveDataTypeable`
`-XGeneralizedNewtypeDeriving` | Enable newtype deriving. | dynamic | `-XNoGeneralizedNewtypeDeriving`
`-XTypeSynonymInstances` | Enable type synonyms. | dynamic | `-XNoTypeSynonymInstances`
`-XFlexibleContexts` | Enable flexible contexts. | dynamic | `-XNoFlexibleContexts`
`-XFlexibleInstances` | Enable flexible instances. | dynamic | `-XNoFlexibleInstances`
`-XConstrainedClassMethods` | Enable constrained class methods. | dynamic | `-XNoConstrainedClassMethods`
`-XMultiParamTypeClasses` | Enable multi parameter type classes. | dynamic | `-XNoMultiParamTypeClasses`
`-XFunctionalDependencies` | Enable functional dependencies. | dynamic | `-XNoFunctionalDependencies`
`-XPackageImports` | Enable package-qualified imports. | dynamic | `-XNoPackageImports`

### 4.17.13. Warnings

Section 4.7, “Warnings and sanity-checking”

Flag | Description | Static/Dynamic | Reverse
--- | --- | --- | ---
`-W` | enable normal warnings | dynamic | `-w`
`-w` | disable all warnings | dynamic | -
`-Wall` | enable almost all warnings (details in Section 4.7, “Warnings and sanity-checking”) | dynamic | `-w`
`-Werror` | make warnings fatal | dynamic | -Wwarn
`-Wwarn` | make warnings non-fatal | dynamic | -Werror
`-fwarn-unrecognised-pragmas` | warn about uses of pragmas that GHC doesn't recognise | dynamic | `-fno-warn-unrecognised-pragmas`
`-fwarn-warnings-deprecations` | warn about uses of functions & types that have warnings or deprecated pragmas | dynamic | `-fno-warn-warnings-deprecations`
`-fwarn-deprecated-flags` | warn about uses of commandline flags that are deprecated | dynamic | `-fno-warn-deprecated-flags`
`-fwarn-duplicate-exports` | warn when an entity is exported multiple times | dynamic | `-fno-warn-duplicate-exports`
`-fwarn-hi-shadowing` | warn when a `.hi` file in the current directory shadows a library | dynamic | `-fno-warn-hi-shadowing`
`-fwarn-implicit-prelude` | warn when the Prelude is implicitly imported | dynamic | `-fno-warn-implicit-prelude`
`-fwarn-incomplete-patterns` | warn when a pattern match could fail | dynamic | `-fno-warn-incomplete-patterns`
`-fwarn-incomplete-record-updates` | warn when a record update could fail | dynamic | `-fno-warn-incomplete-record-updates`
`-fwarn-missing-fields` | warn when fields of a record are uninitialised | dynamic | `-fno-warn-missing-fields`
`-fwarn-missing-methods` | warn when class methods are undefined | dynamic | `-fno-warn-missing-methods`
`-fwarn-missing-signatures` | warn about top-level functions without signatures | dynamic | `-fno-warn-missing-signatures`
`-fwarn-name-shadowing` | warn when names are shadowed | dynamic | `-fno-warn-name-shadowing`
`-fwarn-orphans` | warn when the module contains orphan instance declarations or rewrite rules | dynamic | `-fno-warn-orphans`
`-fwarn-overlapping-patterns` | warn about overlapping patterns | dynamic | `-fno-warn-overlapping-patterns`
`-fwarn-simple-patterns` | warn about lambda-patterns that can fail | dynamic | `-fno-warn-simple-patterns`
`-fwarn-tabs` | warn if there are tabs in the source file | dynamic | `-fno-warn-tabs`
`-fwarn-type-defaults` | warn when defaulting happens | dynamic | `-fno-warn-type-defaults`
`-fwarn-monomorphism-restriction` | warn when the Monomorphism Restriction is applied | dynamic | `-fno-warn-monomorphism-restriction`
`-fwarn-unused-binds` | warn about bindings that are unused | dynamic | `-fno-warn-unused-binds`
`-fwarn-unused-imports` | warn about unnecessary imports | dynamic | `-fno-warn-unused-imports`
`-fwarn-unused-matches` | warn about variables in patterns that aren't used | dynamic | `-fno-warn-unused-matches`

### 4.17.14. Optimisation levels

Section 4.9, “Optimisation (code improvement)”

Flag | Description | Static/Dynamic | Reverse
--- | --- | --- | ---
`-O` | Enable default optimisation (level 1) | dynamic | `-O0`
`-O` `n` | Set optimisation level `n` | dynamic | `-O0`

### 4.17.15. Individual optimisations

Section 4.9.2, “`-f*`: platform-independent flags”

Flag | Description | Static/Dynamic | Reverse
--- | --- | --- | ---
`-fcase-merge` | Enable case-merging. Implied by `-O`. | dynamic | `-fno-case-merge`
`-fdicts-strict` | Make dictionaries strict | static | `-fno-dicts-strict`
`-fmethod-sharing` | Share specialisations of overloaded functions (default) | dynamic | `-fno-method-sharing`
`-fdo-eta-reduction` | Enable eta-reduction. Implied by `-O`. | dynamic | `-fno-do-eta-reduction`
`-fdo-lambda-eta-expansion` | Enable lambda eta-reduction | dynamic | `-fno-do-lambda-eta-expansion`
`-fexcess-precision` | Enable excess intermediate precision | dynamic | `-fno-excess-precision`
`-fignore-asserts` | Ignore assertions in the source | dynamic | `-fno-ignore-asserts`
`-fignore-interface-pragmas` | Ignore pragmas in interface files | dynamic | `-fno-ignore-interface-pragmas`
`-fomit-interface-pragmas` | Don't generate interface pragmas | dynamic | `-fno-omit-interface-pragmas`
`-fmax-worker-args` | If a worker has that many arguments, none will be unpacked anymore (default: 10) | static | -
`-fsimplifier-phases` | Set the number of phases for the simplifier (default 2). Ignored with `-O0`. | dynamic | -
`-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 | -
`-fcse` | Turn on common sub-expression elimination. Implied by `-O`. | dynamic | -fno-cse
`-ffull-laziness` | Turn on full laziness (floating bindings outwards). Implied by `-O`. | dynamic | -fno-full-laziness
`-frewrite-rules` | Switch on all rewrite rules (including rules generated by automatic specialisation of overloaded functions). Implied by `-O`. | dynamic | `-fno-rewrite-rules`
`-fstrictness` | Turn on strictness analysis. Implied by `-O`. | dynamic | -fno-strictness
`-fspec-constr` | Turn on the SpecConstr transformation. Implied by `-O2`. | dynamic | -fno-spec-constr
`-fspec-constr-threshold`=`n` | Set the size threshold for the SpecConstr transformation to `n` (default: 200) | static | `-fno-spec-constr-threshold`
`-fspec-constr-count`=`n` | Set to `n` (default: 3) the maximum number of specialisations that will be created for any one function by the SpecConstr transformation | static | `-fno-spec-constr-count`
`-fliberate-case` | Turn on the liberate-case transformation. Implied by `-O2`. | dynamic | -fno-liberate-case
`-fstatic-argument-transformation` | Turn on the static argument transformation. Implied by `-O2`. | dynamic | -fno-static-argument-transformation
`-fliberate-case-threshold`=`n` | Set the size threshold for the liberate-case transformation to `n` (default: 200) | static | `-fno-liberate-case-threshold`
`-funbox-strict-fields` | Flatten strict constructor fields | dynamic | `-fno-unbox-strict-fields`
`-funfolding-creation-threshold` | Tweak unfolding settings | static | `-fno-unfolding-creation-threshold`
`-funfolding-fun-discount` | Tweak unfolding settings | static | `-fno-unfolding-fun-discount`
`-funfolding-keeness-factor` | Tweak unfolding settings | static | `-fno-unfolding-keeness-factor`
`-funfolding-use-threshold` | Tweak unfolding settings | static | `-fno-unfolding-use-threshold`
`-fno-pre-inlining` | Turn off pre-inlining | static | -

### 4.17.16. Profiling options

Chapter 5, Profiling

Flag | Description | Static/Dynamic | Reverse
--- | --- | --- | ---
`-auto` | Auto-add `_scc_`s to all exported functions | static | `-no-auto`
`-auto-all` | Auto-add `_scc_`s to all top-level functions | static | `-no-auto-all`
`-caf-all` | Auto-add `_scc_`s to all CAFs | static | `-no-caf-all`
`-prof` | Turn on profiling | static | -
`-ticky` | Turn on ticky-ticky profiling | static | -

### 4.17.17. Program coverage options

Section 5.6, “Observing Code Coverage”

Flag | Description | Static/Dynamic | Reverse
--- | --- | --- | ---
`-fhpc` | Turn on Haskell program coverage instrumentation | static | `-`
`-hpcdir dir` | Directory to deposit .mix files during compilation (default is .hpc) | dynamic | `-`

### 4.17.18. Haskell pre-processor options

Section 4.10.4, “Options affecting a Haskell pre-processor”

Flag | Description | Static/Dynamic | Reverse
--- | --- | --- | ---
`-F` | Enable the use of a pre-processor (set with `-pgmF`) | dynamic | -

### 4.17.19. C pre-processor options

Section 4.10.3, “Options affecting the C pre-processor”

Flag | Description | Static/Dynamic | Reverse
--- | --- | --- | ---
`-cpp` | Run the C pre-processor on Haskell source files | dynamic | -
`-D` `symbol`[=`value`] | Define a symbol in the C pre-processor | dynamic | `-U` `symbol`
`-U` `symbol` | Undefine a symbol in the C pre-processor | dynamic | -
`-I` `dir` | Add `dir` to the directory search list for `#include` files | dynamic | -

### 4.17.20. C compiler options

Section 4.10.5, “Options affecting the C compiler (if applicable)”

Flag | Description | Static/Dynamic | Reverse
--- | --- | --- | ---
`-#include` `file` | Include `file` when compiling the `.hc` file | dynamic | -

### 4.17.21. Code generation options

Section 4.10.6, “Options affecting code generation”

Flag | Description | Static/Dynamic | Reverse
--- | --- | --- | ---
`-fasm` | Use the native code generator | dynamic | -fvia-C
`-fvia-C` | Compile via C | dynamic | -fasm
`-fno-code` | Omit code generation | dynamic | -
`-fbyte-code` | Generate byte-code | dynamic | -
`-fobject-code` | Generate object code | dynamic | -

### 4.17.22. Linking options

Section 4.10.7, “Options affecting linking”

Flag | Description | Static/Dynamic | Reverse
--- | --- | --- | ---
`-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 | -
`-l` `lib` | Link in library `lib` | dynamic | -
`-L` `dir` | Add `dir` to the list of directories searched for libraries | dynamic | -
`-main-is` | Set main module and 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 | -
`-fno-gen-manifest` | Do not generate a manifest file (Windows only) | dynamic | -
`-fno-embed-manifest` | Do not embed the manifest in the executable (Windows only) | dynamic | -

### 4.17.23. Replacing phases

Section 4.10.1, “Replacing the program for one or more phases”

Flag | Description | Static/Dynamic | Reverse
--- | --- | --- | ---
`-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 | -
`-pgmwindres` `cmd` | Use `cmd` as the program for embedding manifests on Windows. | dynamic | -

### 4.17.24. Forcing options to particular phases

Section 4.10.2, “Forcing options to a particular phase”

Flag | Description | Static/Dynamic | Reverse
--- | --- | --- | ---
`-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 | -
`-optwindres` `option` | pass `option` to `windres`. | dynamic | -

### 4.17.25. Platform-specific options

Section 4.13, “Platform-specific Flags”

Flag | Description | Static/Dynamic | Reverse
--- | --- | --- | ---
`-monly-[432]-regs` | (x86 only) give some registers back to the C compiler | dynamic | -

### 4.17.26. External core file options

Section 4.15, “Generating and compiling External Core Files”

Flag | Description | Static/Dynamic | Reverse
--- | --- | --- | ---
`-fext-core` | Generate `.hcr` external Core files | static | -

### 4.17.27. Compiler debugging options

Section 4.16, “Debugging the compiler”

Flag | Description | Static/Dynamic | Reverse
--- | --- | --- | ---
`-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-hpc` | Dump after instrumentation for program coverage | 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-phases` | Dump output from each simplifier phase | dynamic | -
`-ddump-simpl-iterations` | Dump output from each simplifier iteration | dynamic | -
`-ddump-spec` | Dump specialiser output | dynamic | -
`-ddump-splices` | Dump TH spliced 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 | -
`-dno-debug-output` | Suppress unsolicited debugging output | static | -
`-dppr-debug` | Turn on debug printing (more verbose) | static | -
`-dsuppress-uniques` | Suppress the printing of uniques in debug output (easier to use diff. | 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 | -

### 4.17.28. Misc compiler options

Flag | Description | Static/Dynamic | Reverse
--- | --- | --- | ---
`-fno-hi-version-check` | Don't complain about `.hi` file mismatches | static | -
`-dno-black-holing` | Turn off black holing (probably doesn't work) | 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 | -

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