GHC.Driver.DynFlags

The backend to use (if any).

Whenever you change the backend, also make sure to set ghcLink to something sensible.

NoBackend can be used to avoid generating any output, however, note that:

• If a program uses Template Haskell the typechecker may need to run code from an imported module. To facilitate this, code generation is enabled for modules imported by modules that use template haskell, using the default backend for the platform. See Note [-fno-code mode].

LLVM optimisation level

Verbosity level: see Note [Verbosity levels]

How much debug information to produce

Number of simplifier phases

Max simplifier iterations

Additional demand analysis

The number of modules to compile in parallel If unspecified, compile with a single job.

Enable RTS timing statistics?

The heap size to set.

Maximum number of bindings from the type envt to show in type error messages

Maximum number of hole fits to show in typed hole error messages

Maximum number of refinement hole fits to show in typed hole error messages

Maximum level of refinement for refinement hole fits in typed hole error messages

Maximum number of unmatched patterns to show in non-exhaustiveness warnings

Soft limit on the number of models the pattern match checker checks a pattern against. A safe guard against exponential blow-up.

Multiplier for simplifier ticks

Whether DmdAnal should optimistically put an Unboxed demand on returned products with at most this number of fields

Threshold for SpecConstr

Max number of specialisations for any one function

Max number of specialisations for recursive types Not optional; otherwise ForceSpecConstr can diverge.

Binary literals (e.g. strings) whose size is above this threshold will be dumped in a binary file by the assembler code generator. 0 and Nothing disables this feature. See GHC.StgToCmm.Config.

Threshold for LiberateCase

Arg count for lambda floating See FloatOutSwitches

Maximum number of arguments after lambda lifting a recursive function.

Maximum number of arguments after lambda lifting a non-recursive function.

Lambda lift even when this turns a known call into an unknown call.

Align Cmm functions at this boundary or use default.

Simplification history size

Typechecker maximum stack depth

Number of iterations in the constraints solver Typically only 1 is needed

Number of layers of superclass expansion for givens Should be < solverIterations See Note [Expanding Recursive Superclasses and ExpansionFuel]

Number of layers of superclass expansion for wanteds Should be < givensFuel See Note [Expanding Recursive Superclasses and ExpansionFuel]

Number of layers of superclass expansion for quantified constraints Should be < givensFuel See Note [Expanding Recursive Superclasses and ExpansionFuel]

Target home unit-id

Id of the unit to instantiate

Module instantiations

What the package is called, use with multiple home units

Target way flags from the command line

Indicate if we are now generating dynamic output because of -dynamic-too. This predicate is used to query the appropriate fields (outputFile/dynOutputFile, ways, etc.)

This defaults to 'non-module'. It can be set by GHC.Driver.Pipeline.setDumpPrefix or ghc.GHCi.UI.runStmt based on where its output is going.

Override the dumpPrefix set by GHC.Driver.Pipeline.setDumpPrefix or ghc.GHCi.UI.runStmt. Set by -ddump-file-prefix

Path to store the .mix files

the -fplugin flags given on the command line, in *reverse* order that they're specified on the command line.

the -ffrontend-opt flags given on the command line, in *reverse* order that they're specified on the command line.

External plugins loaded from shared libraries

The -package-db flags given on the command line, In *reverse* order that they're specified on the command line. This is intended to be applied with the list of "initial" package databases derived from GHC_PACKAGE_PATH; see getUnitDbRefs.

The -ignore-package flags from the command line. In *reverse* order that they're specified on the command line.

The -package and -hide-package flags from the command-line. In *reverse* order that they're specified on the command line.

The -plugin-package-id flags from command line. In *reverse* order that they're specified on the command line.

The -trust and -distrust flags. In *reverse* order that they're specified on the command line.

Filepath to the package environment file (if overriding default)

Safe Haskell mode

Unfolding control See Note [Discounts and thresholds] in GHC.Core.Unfold

GHCi scripts specified by -ghci-script, in reverse order

what kind of {-# SCC #-} to add automatically

Machine dependent flags (-m<blah> stuff)

Enable FMA instructions.

Max size, in bytes, of inline array allocations.

Only inline memcpy if it generates no more than this many pseudo (roughly: Cmm) instructions.

Only inline memset if it generates no more than this many pseudo (roughly: Cmm) instructions.

Reverse the order of error messages in GHC/GHCi

Limit the maximum number of errors to show

Unique supply configuration for testing build determinism

Temporary: CFG Edge weights for fast iterations

Bring all exposed modules into scope?

Bring module m into scope under name n.

See Note [Implicit include paths]