GHC.Driver.Flags

Debugging flags

Helper function to query whether a given DumpFlag is enabled or not.

Is the flag implicitly enabled when the verbosity is high enough?

Enumerates the simple on-or-off dynamic flags

The default Language is used if one is not specified explicitly, by both GHC and GHCi.

The set of flags which affect optimisation for the purposes of recompilation avoidance. Specifically, these include flags which affect code generation but not the semantics of the program.

See Note [Ignoring some flag changes] in GHC.Iface.Recomp.Flags)

The set of flags which affect code generation and can change a program's runtime behavior (other than performance). These include flags which affect:

• user visible debugging information (e.g. info table provenance)

• the ability to catch runtime errors (e.g. -fignore-asserts)

• the runtime result of the program (e.g. -fomit-yields)

• which code or interface file declarations are emitted

We also considered placing flags which affect asympototic space behavior (e.g. -ffull-laziness) however this would mean that changing optimisation levels would trigger recompilation even with -fignore-optim-changes, regressing #13604.

Also, arguably Opt_IgnoreAsserts should be here as well; however, we place it instead in optimisationFlags since it is implied by -O[12] and therefore would also break #13604.

See #23369.

A group of warning flags that can be enabled or disabled collectively, e.g. using -Wcompat to enable all warnings in the W_compat group.

Does this warning group contain (all) extended warning categories? See Note [Warning categories] in GHC.Unit.Module.Warnings.

The W_extended_warnings group contains extended warnings but no WarningFlags, but extended warnings are also treated as part of W_default and every warning group that includes it.

Return the names of a WarningFlag

One flag may have several names because of US/UK spelling. The first one is the "preferred one" that will be displayed in warning messages.

Warning groups.

As all warnings are in the W_everything set, it is ignored when displaying to the user which group a warning is in.

Warning group hierarchies, where there is an explicit inclusion relation.

Each inner list is a hierarchy of warning groups, ordered from smallest to largest, where each group is a superset of the one before it.

Separating this from warningGroups allows for multiple hierarchies with no inherent relation to be defined.

The special-case W_everything group is not included.

Find the smallest group in every hierarchy which a warning belongs to, excluding Weverything.

The smallest group in every hierarchy to which a custom warning category belongs is currently always -Wextended-warnings. See Note [Warning categories] in GHC.Unit.Module.Warnings.

Warnings enabled unless specified otherwise

Things you get with -W.

Things you get with -Wall.

Things you get with -Weverything, i.e. *all* known warnings flags.

Things you get with -Wcompat.

This is intended to group together warnings that will be enabled by default at some point in the future, so that library authors eager to make their code future compatible to fix issues before they even generate warnings.

Things you get with -Wunused-binds.

General flags that are switched on/off when other general flags are switched on

General flags that are switched on/off when other general flags are switched off

Always returns Deprecated even when the flag is only conditionally deprecated.

All the names by which an extension is known.