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| author | Simon Peyton Jones <simon.peytonjones@gmail.com> | 2023-03-02 11:26:17 +0000 |
|---|---|---|
| committer | Simon Peyton Jones <simon.peytonjones@gmail.com> | 2023-03-03 08:13:44 +0000 |
| commit | 53c4b80add408db9f305b61a5fe3abe23b0a55e1 (patch) | |
| tree | 5cdfaf6b8289500a3968a086d6f95df3c3cb4156 /compiler/GHC/Core/Lint.hs | |
| parent | 2f97c86151d7eed115ddcbdee1842684aed63176 (diff) | |
| download | haskell-wip/T22023.tar.gz | |
More fixes for `type data` declarationswip/T22023
This MR fixes #23022 and #23023. Specifically
* Beef up Note [Type data declarations] in GHC.Rename.Module,
to make invariant (I1) explicit, and to name the several
wrinkles.
And add references to these specific wrinkles.
* Add a Lint check for invariant (I1) above.
See GHC.Core.Lint.checkTypeDataConOcc
* Disable the `caseRules` for dataToTag# for `type data` values.
See Wrinkle (W2c) in the Note above. Fixes #23023.
* Refine the assertion in dataConRepArgTys, so that it does not
complain about the absence of a wrapper for a `type data` constructor
Fixes #23022.
Acked-by: Simon Peyton Jones <simon.peytonjones@gmail.com>
Diffstat (limited to 'compiler/GHC/Core/Lint.hs')
| -rw-r--r-- | compiler/GHC/Core/Lint.hs | 19 |
1 files changed, 15 insertions, 4 deletions
diff --git a/compiler/GHC/Core/Lint.hs b/compiler/GHC/Core/Lint.hs index 2f7ab56b5b..2465a2ffdf 100644 --- a/compiler/GHC/Core/Lint.hs +++ b/compiler/GHC/Core/Lint.hs @@ -1021,6 +1021,9 @@ lintIdOcc var nargs ; checkDeadIdOcc var ; checkJoinOcc var nargs + ; case isDataConId_maybe var of + Nothing -> return () + Just dc -> checkTypeDataConOcc "expression" dc ; usage <- varCallSiteUsage var @@ -1107,6 +1110,13 @@ checkJoinOcc var n_args | otherwise = return () +checkTypeDataConOcc :: String -> DataCon -> LintM () +-- Check that the Id is not a data constructor of a `type data` declaration +-- Invariant (I1) of Note [Type data declarations] in GHC.Rename.Module +checkTypeDataConOcc what dc + = checkL (not (isTypeDataTyCon (dataConTyCon dc))) $ + (text "type data constructor found in a" <+> text what <> colon <+> ppr dc) + -- | This function checks that we are able to perform eta expansion for -- functions with no binding, in order to satisfy invariant I3 -- from Note [Representation polymorphism invariants] in GHC.Core. @@ -1561,10 +1571,11 @@ lintCoreAlt case_bndr scrut_ty _scrut_mult alt_ty alt@(Alt (DataAlt con) args rh = zeroUE <$ addErrL (mkNewTyDataConAltMsg scrut_ty alt) | Just (tycon, tycon_arg_tys) <- splitTyConApp_maybe scrut_ty = addLoc (CaseAlt alt) $ do - { -- First instantiate the universally quantified - -- type variables of the data constructor - -- We've already check - lintL (tycon == dataConTyCon con) (mkBadConMsg tycon con) + { checkTypeDataConOcc "pattern" con + ; lintL (tycon == dataConTyCon con) (mkBadConMsg tycon con) + + -- Instantiate the universally quantified + -- type variables of the data constructor ; let { con_payload_ty = piResultTys (dataConRepType con) tycon_arg_tys ; binderMult (Named _) = ManyTy ; binderMult (Anon st _) = scaledMult st |