Add support for GHC 9.11.20240522

CHANGELOG.md

@@ -1,3 +1,7 @@
+## 0.5
+* Add `evByFiatWithDependencies`, see https://gitlab.haskell.org/ghc/ghc/-/merge_requests/12037 for more details.
+* Added support for GHC 9.11.20240522
+
 ## 0.4.6 *May 22nd 2024*
 * Added support for GHC-9.10.1
 * Removed support for GHC 7.10

defaults.dhall

@@ -1,5 +1,5 @@
 { name = "ghc-tcplugins-extra"
-, version = "0.4.6"
+, version = "0.5"
 , synopsis = "Utilities for writing GHC type-checker plugins"
 , description =
     ''

ghc-tcplugins-extra.cabal

@@ -5,7 +5,7 @@ cabal-version: 2.0
 -- see: https://github.com/sol/hpack
 
 name:           ghc-tcplugins-extra
-version:        0.4.6
+version:        0.5
 synopsis:       Utilities for writing GHC type-checker plugins
 description:    Utilities for writing GHC type-checker plugins, such as
                 creating constraints, with a stable API covering multiple
@@ -55,7 +55,20 @@ library
     ghc-options: -fhide-source-paths
   if flag(deverror)
     ghc-options: -Werror
-  if impl(ghc >= 9.10) && impl(ghc < 9.12)
+  if impl(ghc >= 9.11) && impl(ghc < 9.13)
+    other-modules:
+        GhcApi.Constraint
+        GhcApi.Predicate
+        GhcApi.GhcPlugins
+        Internal.Type
+        Internal.Constraint
+        Internal.Evidence
+    hs-source-dirs:
+        src-ghc-tree-9.12
+        src-ghc-9.12
+    build-depends:
+        ghc >=9.11 && <9.13
+  if impl(ghc >= 9.10) && impl(ghc < 9.11)
     other-modules:
         GhcApi.Constraint
         GhcApi.Predicate
@@ -67,7 +80,7 @@ library
         src-ghc-tree-9.4
         src-ghc-9.10
     build-depends:
-        ghc >=9.10 && <9.12
+        ghc ==9.10.*
   if impl(ghc >= 9.8) && impl(ghc < 9.10)
     other-modules:
         GhcApi.Constraint

package.dhall

@@ -30,7 +30,8 @@ in  let ghc = { name = "ghc", mixin = [] : List Text }
                       , exposed-modules = "GHC.TcPluginM.Extra"
                       , other-modules = "Internal"
                       , when =
-                        [ version "9.10" "9.12" [ "tree-9.4", "9.10" ] ghc mods
+                        [ version "9.11" "9.13" [ "tree-9.12", "9.12" ] ghc mods
+                        , version "9.10" "9.11" [ "tree-9.4", "9.10" ] ghc mods
                         , version "9.8" "9.10" [ "tree-9.4", "9.8" ] ghc mods
                         , version "9.4" "9.8" [ "tree-9.4", "9.4" ] ghc mods
                         , version "9.2" "9.4" [ "tree", "9.2" ] ghc mods

src-ghc-9.12/GhcApi/Constraint.hs

@@ -0,0 +1,13 @@
+module GhcApi.Constraint
+  ( Ct(..)
+  , CtEvidence(..)
+  , CtLoc
+  , CanEqLHS(..)
+  , ctLoc
+  , ctEvId
+  , mkNonCanonical
+  )
+where
+
+import GHC.Tc.Types.Constraint
+  (Ct (..), CtEvidence (..), CanEqLHS (..), CtLoc, ctLoc, ctEvId, mkNonCanonical)

src-ghc-9.12/GhcApi/GhcPlugins.hs

@@ -0,0 +1,5 @@
+module GhcApi.GhcPlugins (module GHC.Plugins, FindResult(..), findPluginModule) where
+
+import GHC.Plugins hiding (TcPlugin)
+import GHC.Unit.Finder (findPluginModule)
+import GHC.Tc.Plugin (FindResult(..))

src-ghc-9.12/Internal/Constraint.hs

@@ -0,0 +1,64 @@
+{-# LANGUAGE RecordWildCards #-}
+
+module Internal.Constraint (newGiven, flatToCt, mkSubst, overEvidencePredType) where
+
+import GhcApi.GhcPlugins
+import GhcApi.Constraint
+  (Ct(..), CtEvidence(..), CanEqLHS(..), CtLoc, ctLoc, ctEvId, mkNonCanonical)
+
+import GHC.Tc.Utils.TcType (TcType)
+import GHC.Tc.Types.Constraint (DictCt(..), IrredCt(..), EqCt(..), QCInst(..))
+import GHC.Tc.Types.Evidence (EvTerm(..), EvBindsVar)
+import GHC.Tc.Plugin (TcPluginM)
+import qualified GHC.Tc.Plugin as TcPlugin (newGiven)
+
+-- | Create a new [G]iven constraint, with the supplied evidence. This must not
+-- be invoked from 'tcPluginInit' or 'tcPluginStop', or it will panic.
+newGiven :: EvBindsVar -> CtLoc -> PredType -> EvTerm -> TcPluginM CtEvidence
+newGiven tcEvbinds loc pty (EvExpr ev) = TcPlugin.newGiven tcEvbinds loc pty ev
+newGiven _ _ _ ev = panicDoc "newGiven: not an EvExpr: " (ppr ev)
+
+flatToCt :: [((TcTyVar,TcType),Ct)] -> Maybe Ct
+flatToCt [((_,lhs),ct),((_,rhs),_)]
+    = Just
+    $ mkNonCanonical
+    $ CtGiven (mkPrimEqPred lhs rhs)
+              (ctEvId ct)
+              (ctLoc ct)
+
+flatToCt _ = Nothing
+
+-- | Create simple substitution from type equalities
+mkSubst :: Ct -> Maybe ((TcTyVar, TcType),Ct)
+mkSubst ct@(CEqCan (EqCt {..}))
+  | TyVarLHS tyvar <- eq_lhs
+  = Just ((tyvar,eq_rhs),ct)
+mkSubst _ = Nothing
+
+-- | Modify the predicate type of the evidence term of a constraint
+overEvidencePredType :: (TcType -> TcType) -> Ct -> Ct
+overEvidencePredType f (CDictCan di) =
+  let
+    ev :: CtEvidence
+    ev = di_ev di
+  in CDictCan ( di { di_ev = ev { ctev_pred = f (ctev_pred ev) } } )
+overEvidencePredType f (CIrredCan ir) =
+  let
+    ev :: CtEvidence
+    ev = ir_ev ir
+  in CIrredCan ( ir { ir_ev = ev { ctev_pred = f (ctev_pred ev) } } )
+overEvidencePredType f (CEqCan eq) =
+  let
+    ev :: CtEvidence
+    ev = eq_ev eq
+  in CEqCan ( eq { eq_ev = ev { ctev_pred = f (ctev_pred ev) } } )
+overEvidencePredType f (CNonCanonical ct) =
+  let
+    ev :: CtEvidence
+    ev = ct
+  in CNonCanonical ( ev { ctev_pred = f (ctev_pred ev) } )
+overEvidencePredType f (CQuantCan qci) =
+  let
+    ev :: CtEvidence
+    ev = qci_ev qci
+  in CQuantCan ( qci { qci_ev = ev { ctev_pred = f (ctev_pred ev) } } )

src-ghc-9.12/Internal/Evidence.hs

@@ -0,0 +1,26 @@
+module Internal.Evidence (evByFiat, evByFiatWithDependencies) where
+
+import GHC.Tc.Types.Evidence (EvTerm(..))
+import GHC.Core.TyCo.Rep (UnivCoProvenance (..))
+
+import GhcApi.GhcPlugins
+
+-- | The 'EvTerm' equivalent for 'Unsafe.unsafeCoerce'
+evByFiat :: String -- ^ Name the coercion should have
+         -> Type   -- ^ The LHS of the equivalence relation (~)
+         -> Type   -- ^ The RHS of the equivalence relation (~)
+         -> EvTerm
+evByFiat name t1 t2 =
+  EvExpr $ Coercion $ mkUnivCo (PluginProv name emptyDVarSet) Nominal t1 t2
+{-# DEPRECATED evByFiat "'evByFiat' creates proofs that can lead to unsoundness, use 'evByFiatWithDependencies' instead.\nSee also https://gitlab.haskell.org/ghc/ghc/-/merge_requests/12037" #-}
+
+-- | The 'EvTerm' equivalent for 'Unsafe.unsafeCoerce'
+evByFiatWithDependencies ::
+  String -- ^ Name the coercion should have
+  -> DCoVarSet -- ^ The set of all the in-scope coercion variables
+               -- that the proof makes use of.
+  -> Type -- ^ The LHS of the equivalence relation (~)
+  -> Type -- ^ The RHS of the equivalence relation (~)
+  -> EvTerm
+evByFiatWithDependencies name deps t1 t2 =
+  EvExpr $ Coercion $ mkUnivCo (PluginProv name deps) Nominal t1 t2

src-ghc-9.12/Internal/Type.hs

@@ -0,0 +1,30 @@
+module Internal.Type (substType) where
+
+import Data.Maybe (fromMaybe)
+import GHC.Tc.Utils.TcType (TcType)
+import GHC.Core.TyCo.Rep (Type (..))
+import GHC.Types.Var (TcTyVar)
+
+-- | Apply substitutions in Types
+--
+-- __NB:__ Doesn't substitute under binders
+substType
+  :: [(TcTyVar, TcType)]
+  -> TcType
+  -> TcType
+substType subst tv@(TyVarTy v) =
+  fromMaybe tv (lookup v subst)
+substType subst (AppTy t1 t2) =
+  AppTy (substType subst t1) (substType subst t2)
+substType subst (TyConApp tc xs) =
+  TyConApp tc (map (substType subst) xs)
+substType _subst t@(ForAllTy _tv _ty) =
+  -- TODO: Is it safe to do "dumb" substitution under binders?
+  -- ForAllTy tv (substType subst ty)
+  t
+substType subst (FunTy k1 k2 t1 t2) =
+  FunTy k1 k2 (substType subst t1) (substType subst t2)
+substType _ l@(LitTy _) = l
+substType subst (CastTy ty co) =
+  CastTy (substType subst ty) co
+substType _ co@(CoercionTy _) = co

src-ghc-tree-9.12/GhcApi/Predicate.hs

@@ -0,0 +1,3 @@
+module GhcApi.Predicate (mkPrimEqPred) where
+
+import GHC.Core.Coercion (mkPrimEqPred)

src-ghc-tree-9.12/Internal.hs

@@ -0,0 +1,134 @@
+{-# LANGUAGE RecordWildCards #-}
+
+{-# OPTIONS_HADDOCK show-extensions #-}
+
+module Internal
+  ( -- * Create new constraints
+    TcPlugin.newWanted
+  , newGiven
+    -- * Creating evidence
+  , evByFiatWithDependencies
+  , evByFiat
+    -- * Lookup
+  , lookupModule
+  , lookupName
+    -- * Trace state of the plugin
+  , tracePlugin
+    -- * Substitutions
+  , flattenGivens
+  , mkSubst
+  , mkSubst'
+  , substType
+  , substCt
+  )
+where
+
+import GHC.Driver.Config.Finder (initFinderOpts)
+import GHC.Tc.Plugin (TcPluginM, lookupOrig, tcPluginTrace)
+import qualified GHC.Tc.Plugin as TcPlugin
+  (newWanted, getTopEnv, tcPluginIO, findImportedModule)
+import GHC.Tc.Types (TcPlugin(..), TcPluginSolveResult(..))
+import Control.Arrow (first, second)
+import Data.Function (on)
+import Data.List (groupBy, partition, sortOn)
+import GHC.Tc.Utils.TcType (TcType)
+import Data.Maybe (mapMaybe)
+
+import GhcApi.Constraint (Ct(..))
+import GhcApi.GhcPlugins
+
+import Internal.Type (substType)
+import Internal.Constraint (newGiven, flatToCt, mkSubst, overEvidencePredType)
+import Internal.Evidence (evByFiat, evByFiatWithDependencies)
+
+-- | Find a module
+lookupModule :: ModuleName -- ^ Name of the module
+             -> FastString -- ^ Name of the package containing the module.
+                           -- NOTE: This value is ignored on ghc>=8.0.
+             -> TcPluginM Module
+lookupModule mod_nm _pkg = do
+  hsc_env <- TcPlugin.getTopEnv
+  let fc         = hsc_FC hsc_env
+      dflags     = hsc_dflags hsc_env
+      fopts      = initFinderOpts dflags
+      units      = hsc_units hsc_env
+      mhome_unit = hsc_home_unit_maybe hsc_env
+  found_module <- TcPlugin.tcPluginIO $ findPluginModule fc fopts units
+                                          mhome_unit mod_nm
+  case found_module of
+    Found _ h -> return h
+    _ -> do
+      let pkg_qual = maybe NoPkgQual (ThisPkg . homeUnitId) mhome_unit
+      found_module' <- TcPlugin.findImportedModule mod_nm pkg_qual
+      case found_module' of
+        Found _ h -> return h
+        _ -> panicDoc "Couldn't find module" (ppr mod_nm)
+
+-- | Find a 'Name' in a 'Module' given an 'OccName'
+lookupName :: Module -> OccName -> TcPluginM Name
+lookupName = lookupOrig
+
+-- | Print out extra information about the initialisation, stop, and every run
+-- of the plugin when @-ddump-tc-trace@ is enabled.
+tracePlugin :: String -> TcPlugin -> TcPlugin
+tracePlugin s TcPlugin{..} = TcPlugin { tcPluginInit    = traceInit
+                                      , tcPluginSolve   = traceSolve
+                                      , tcPluginRewrite = tcPluginRewrite
+                                      , tcPluginStop    = traceStop
+                                      }
+  where
+    traceInit = do
+      tcPluginTrace ("tcPluginInit " ++ s) empty >> tcPluginInit
+
+    traceStop  z = tcPluginTrace ("tcPluginStop " ++ s) empty >> tcPluginStop z
+
+    traceSolve z ev given wanted = do
+      tcPluginTrace ("tcPluginSolve start " ++ s)
+                        (text "given   =" <+> ppr given
+                      $$ text "wanted  =" <+> ppr wanted)
+      r <- tcPluginSolve z ev given wanted
+      case r of
+        TcPluginOk solved new
+          -> tcPluginTrace ("tcPluginSolve ok " ++ s)
+                           (text "solved =" <+> ppr solved
+                         $$ text "new    =" <+> ppr new)
+        TcPluginContradiction bad
+          -> tcPluginTrace ("tcPluginSolve contradiction " ++ s)
+                           (text "bad =" <+> ppr bad)
+        TcPluginSolveResult bad solved new
+          -> tcPluginTrace ("tcPluginSolveResult " ++ s)
+                           (text "solved =" <+> ppr solved
+                         $$ text "bad    =" <+> ppr bad
+                         $$ text "new    =" <+> ppr new)
+      return r
+
+-- | Flattens evidence of constraints by substituting each others equalities.
+--
+-- __NB:__ Should only be used on /[G]iven/ constraints!
+--
+-- __NB:__ Doesn't flatten under binders
+flattenGivens :: [Ct] -> [Ct]
+flattenGivens givens =
+  mapMaybe flatToCt flat ++ map (substCt subst') givens
+ where
+  subst = mkSubst' givens
+  (flat,subst')
+    = second (map fst . concat)
+    $ partition ((>= 2) . length)
+    $ groupBy ((==) `on` (fst.fst))
+    $ sortOn (fst.fst) subst
+
+-- | Create flattened substitutions from type equalities, i.e. the substitutions
+-- have been applied to each others right hand sides.
+mkSubst' :: [Ct] -> [((TcTyVar,TcType),Ct)]
+mkSubst' = foldr substSubst [] . mapMaybe mkSubst
+ where
+  substSubst :: ((TcTyVar,TcType),Ct)
+             -> [((TcTyVar,TcType),Ct)]
+             -> [((TcTyVar,TcType),Ct)]
+  substSubst ((tv,t),ct) s = ((tv,substType (map fst s) t),ct)
+                           : map (first (second (substType [(tv,t)]))) s
+
+-- | Apply substitution in the evidence of Cts
+substCt :: [(TcTyVar, TcType)] -> Ct -> Ct
+substCt subst = overEvidencePredType (substType subst)