diff options
Diffstat (limited to 'docs/users_guide/using-warnings.rst')
| -rw-r--r-- | docs/users_guide/using-warnings.rst | 36 |
1 files changed, 27 insertions, 9 deletions
diff --git a/docs/users_guide/using-warnings.rst b/docs/users_guide/using-warnings.rst index cea8e9b780..30c86596d1 100644 --- a/docs/users_guide/using-warnings.rst +++ b/docs/users_guide/using-warnings.rst @@ -319,9 +319,8 @@ of ``-W(no-)*``. .. ghc-flag:: -Wpartial-type-signatures :shortdesc: warn about holes in partial type signatures when :extension:`PartialTypeSignatures` is enabled. Not applicable when - :extension:`PartialTypesignatures` is not enabled, in which case - errors are generated for such holes. See - :ref:`partial-type-signatures`. + :extension:`PartialTypeSignatures` is not enabled, in which case + errors are generated for such holes. :type: dynamic :reverse: -Wno-partial-type-signatures :category: @@ -643,15 +642,15 @@ of ``-W(no-)*``. .. ghc-flag:: -Wderiving-defaults :shortdesc: warn about default deriving when using both - DeriveAnyClass and GeneralizedNewtypeDeriving + :extension:`DeriveAnyClass` and :extension:`GeneralizedNewtypeDeriving` :type: dynamic :reverse: -Wno-deriving-defaults :category: :since: 8.10 - Causes a warning when both :ref:`DeriveAnyClass` and - :ref:`GeneralizedNewtypeDeriving` are enabled and no explicit + Causes a warning when both :extension:`DeriveAnyClass` and + :extension:`GeneralizedNewtypeDeriving` are enabled and no explicit deriving strategy is in use. For example, this would result a warning: :: @@ -756,6 +755,24 @@ of ``-W(no-)*``. probably no-ops and can be omitted. The functions checked for are: ``toInteger``, ``toRational``, ``fromIntegral``, and ``realToFrac``. +.. ghc-flag:: -Wimplicit-kind-vars + :shortdesc: warn when kind variables are implicitly quantified over. + :type: dynamic + :reverse: -Wno-implicit-kind-vars + :category: + + .. index:: + single: implicit prelude, warning + + Have the compiler warn if a kind variable is not explicitly quantified + over. For instance, the following would produce a warning: :: + + f :: forall (a :: k). Proxy a + + This can be fixed by explicitly quantifying over ``k``: :: + + f :: forall k (a :: k). Proxy a + .. ghc-flag:: -Wimplicit-prelude :shortdesc: warn when the Prelude is implicitly imported :type: dynamic @@ -835,7 +852,7 @@ of ``-W(no-)*``. ``Just y`` but ``y`` is not ``4``. This can be exponential in the arity of the pattern and in the number of - guards in some cases. The :ghc-flag:`-fmax-pmcheck-models` limit makes sure + guards in some cases. The :ghc-flag:`-fmax-pmcheck-models=⟨n⟩` limit makes sure we scale polynomially in the number of patterns, by forgetting refined information gained from a partially successful match. For the above example, if we had a limit of 1, we would continue checking the next clause with the @@ -1705,8 +1722,9 @@ of ``-W(no-)*``. :since: 8.8 The option :ghc-flag:`-Wunused-packages` warns about packages, specified on - command line via :ghc-flag:`-package` or :ghc-flag:`-package-id`, but were not - loaded during compication. Usually it means that you have an unused dependency. + command line via :ghc-flag:`-package ⟨pkg⟩` or + :ghc-flag:`-package-id ⟨unit-id⟩`, but were not loaded during compication. + Usually it means that you have an unused dependency. You may want to enable this warning on a clean build or enable :ghc-flag:`-fforce-recomp` in order to get reliable results. |