ghc-tcplugin-api 0.7.0.0 → 0.7.1.0

raw patch · 3 files changed

+25/−16 lines, 3 filesPVP: major bump suggested

API removals or changes: PVP suggests a major version bump

API changes (from Hackage documentation)

Files

• changelog.md +11/−0
• ghc-tcplugin-api.cabal +1/−1
• src/GHC/TcPlugin/API.hs +13/−15

@@ -1,4 +1,15 @@ 
+# Version 0.7.1.0 (2022-01-04)
+
+- `newWanted` now always uses the `CtLoc` information that it is provided with,
+  as opposed to obtaining some information from the monadic environment.
+  This means you no longer need to wrap calls to `newWanted` in `setCtLocM`
+  to ensure that GHC reports the correct source span when reporting unsolved
+  Wanteds in error messages.
+
+- Remove the `newDerived` function, as Derived constraints are going to be
+  removed from GHC.
+
 # Version 0.7.0.0 (2021-12-31)
 
 - Re-export functions for dealing with type-level literals,

@@ -1,6 +1,6 @@ cabal-version:  3.0
 name:           ghc-tcplugin-api
-version:        0.7.0.0
+version:        0.7.1.0
 synopsis:       An API for type-checker plugins.
 license:        BSD-3-Clause
 build-type:     Simple

@@ -315,7 +315,7 @@     --
     -- GHC 9.4 removes this flavour of constraints entirely, subsuming their uses into
     -- Wanted constraints.
-  , askDeriveds, newDerived
+  , askDeriveds
 
     -- ** Location information and 'CtLoc's
 
@@ -786,24 +786,23 @@ 
 --------------------------------------------------------------------------------
 
--- | Create a new derived constraint.
+-- | Create a new Wanted constraint.
 --
 -- Requires a location (so that error messages can say where the constraint came from,
 -- what things were in scope at that point, etc), as well as the actual constraint (encoded as a type).
 newWanted :: MonadTcPluginWork m => CtLoc -> PredType -> m CtEvidence
-newWanted loc pty = liftTcPluginM $ GHC.newWanted loc pty
-
--- | Create a new derived constraint. See also 'newWanted'.
-newDerived :: MonadTcPluginWork m => CtLoc -> PredType -> m CtEvidence
-newDerived loc pty = liftTcPluginM $ GHC.newDerived loc pty
+newWanted loc pty =
+#if !HAS_REWRITING
+  -- On GHC 9.2 and below, 'newWanted' doesn't use the location information
+  -- that is passed to it, retrieving it from the 'TcM' environment instead.
+  -- https://gitlab.haskell.org/ghc/ghc/-/issues/20895
+  setCtLocM loc $
+#endif
+  liftTcPluginM $ GHC.newWanted loc pty
 
--- | Create a new given constraint.
---
--- Unlike 'newWanted' and 'newDerived', we need to supply evidence
--- for this constraint.
+-- | Create a new Given constraint.
 --
--- Use 'setCtLocM' to pass along the location information,
--- as only the 'CtOrigin' gets taken into account here.
+-- Unlike 'newWanted', we need to supply evidence for this constraint.
 newGiven :: CtLoc -> PredType -> EvExpr -> TcPluginM Solve CtEvidence
 newGiven loc pty evtm = do
 #if HAS_REWRITING
@@ -823,8 +822,7 @@ rewriteEnvCtLoc :: RewriteEnv -> CtLoc
 rewriteEnvCtLoc = fe_loc
 
--- | Set the location information for a computation,
--- so that the constraint solver reports an error at the given location.
+-- | Set the location information for a computation.
 setCtLocM :: MonadTcPluginWork m => CtLoc -> m a -> m a
 setCtLocM loc = unsafeLiftThroughTcM ( GHC.setCtLocM loc )