{-# LANGUAGE LambdaCase #-}
{-# LANGUAGE TypeFamilies #-}

{-# OPTIONS_GHC -Wno-incomplete-uni-patterns   #-}

{-
(c) The GRASP/AQUA Project, Glasgow University, 1992-1998

Renaming and dependency analysis of bindings

This module does renaming and dependency analysis on value bindings in
the abstract syntax.  It does {\em not} do cycle-checks on class or
type-synonym declarations; those cannot be done at this stage because
they may be affected by renaming (which isn't fully worked out yet).
-}

module GHC.Rename.Bind (
   -- Renaming top-level bindings
   rnTopBindsLHS, rnTopBindsLHSBoot, rnTopBindsBoot, rnValBindsRHS,

   -- Renaming local bindings
   rnLocalBindsAndThen, rnLocalValBindsLHS, rnLocalValBindsRHS,

   -- Other bindings
   rnMethodBinds, renameSigs,
   rnMatchGroup, rnGRHSs, rnGRHS, rnSrcFixityDecl,
   makeMiniFixityEnv, MiniFixityEnv, emptyMiniFixityEnv,
   HsSigCtxt(..),

   -- Utility for hs-boot files
   rejectBootDecls,

   -- Utility for COMPLETE pragmas
   localCompletePragmas
   ) where

import GHC.Prelude

import {-# SOURCE #-} GHC.Rename.Expr( rnExpr, rnLExpr, rnStmts )

import GHC.Hs
import GHC.Tc.Errors.Types
import GHC.Tc.Utils.Monad
import GHC.Rename.HsType
import GHC.Rename.Pat
import GHC.Rename.Names
import GHC.Rename.Env
import GHC.Rename.Fixity
import GHC.Rename.Utils ( mapFvRn
                        , checkDupRdrNames
                        , warnUnusedLocalBinds
                        , checkUnusedRecordWildcard
                        , checkDupAndShadowedNames, bindLocalNamesFV
                        , addNoNestedForallsContextsErr, checkInferredVars )
import GHC.Driver.DynFlags
import GHC.Unit.Module
import GHC.Types.Error
import GHC.Types.FieldLabel
import GHC.Types.Name
import GHC.Types.Name.Env
import GHC.Types.Name.Set
import GHC.Types.Name.Reader ( RdrName, rdrNameOcc )
import GHC.Types.SourceFile
import GHC.Types.SrcLoc as SrcLoc
import GHC.Data.List.SetOps    ( findDupsEq )
import GHC.Types.Basic         ( RecFlag(..), TypeOrKind(..) )
import GHC.Data.Graph.Directed ( SCC(..) )
import GHC.Utils.Misc
import GHC.Utils.Outputable
import GHC.Utils.Panic
import GHC.Types.CompleteMatch
import GHC.Types.Unique.Set
import GHC.Data.Maybe          ( orElse, mapMaybe )
import GHC.Data.OrdList
import qualified GHC.LanguageExtensions as LangExt

import Language.Haskell.Syntax.Basic (FieldLabelString(..))

import Control.Monad
import Data.List          ( partition )
import Data.List.NonEmpty ( NonEmpty(..) )
import GHC.Types.Unique.DSet (mkUniqDSet)

{-
-- ToDo: Put the annotations into the monad, so that they arrive in the proper
-- place and can be used when complaining.

The code tree received by the function @rnBinds@ contains definitions
in where-clauses which are all apparently mutually recursive, but which may
not really depend upon each other. For example, in the top level program
\begin{verbatim}
f x = y where a = x
              y = x
\end{verbatim}
the definitions of @a@ and @y@ do not depend on each other at all.
Unfortunately, the typechecker cannot always check such definitions.
\footnote{Mycroft, A. 1984. Polymorphic type schemes and recursive
definitions. In Proceedings of the International Symposium on Programming,
Toulouse, pp. 217-39. LNCS 167. Springer Verlag.}
However, the typechecker usually can check definitions in which only the
strongly connected components have been collected into recursive bindings.
This is precisely what the function @rnBinds@ does.

ToDo: deal with case where a single monobinds binds the same variable
twice.

The vertag tag is a unique @Int@; the tags only need to be unique
within one @MonoBinds@, so that unique-Int plumbing is done explicitly
(heavy monad machinery not needed).


************************************************************************
*                                                                      *
* naming conventions                                                   *
*                                                                      *
************************************************************************

\subsection[name-conventions]{Name conventions}

The basic algorithm involves walking over the tree and returning a tuple
containing the new tree plus its free variables. Some functions, such
as those walking polymorphic bindings (HsBinds) and qualifier lists in
list comprehensions (@Quals@), return the variables bound in local
environments. These are then used to calculate the free variables of the
expression evaluated in these environments.

Conventions for variable names are as follows:
\begin{itemize}
\item
new code is given a prime to distinguish it from the old.

\item
a set of variables defined in @Exp@ is written @dvExp@

\item
a set of variables free in @Exp@ is written @fvExp@
\end{itemize}

************************************************************************
*                                                                      *
* analysing polymorphic bindings (HsBindGroup, HsBind)
*                                                                      *
************************************************************************

\subsubsection[dep-HsBinds]{Polymorphic bindings}

Non-recursive expressions are reconstructed without any changes at top
level, although their component expressions may have to be altered.
However, non-recursive expressions are currently not expected as
\Haskell{} programs, and this code should not be executed.

Monomorphic bindings contain information that is returned in a tuple
(a @FlatMonoBinds@) containing:

\begin{enumerate}
\item
a unique @Int@ that serves as the ``vertex tag'' for this binding.

\item
the name of a function or the names in a pattern. These are a set
referred to as @dvLhs@, the defined variables of the left hand side.

\item
the free variables of the body. These are referred to as @fvBody@.

\item
the definition's actual code. This is referred to as just @code@.
\end{enumerate}

The function @nonRecDvFv@ returns two sets of variables. The first is
the set of variables defined in the set of monomorphic bindings, while the
second is the set of free variables in those bindings.

The set of variables defined in a non-recursive binding is just the
union of all of them, as @union@ removes duplicates. However, the
free variables in each successive set of cumulative bindings is the
union of those in the previous set plus those of the newest binding after
the defined variables of the previous set have been removed.

@rnMethodBinds@ deals only with the declarations in class and
instance declarations.  It expects only to see @FunMonoBind@s, and
it expects the global environment to contain bindings for the binders
(which are all class operations).

************************************************************************
*                                                                      *
\subsubsection{ Top-level bindings}
*                                                                      *
************************************************************************
-}

-- for top-level bindings, we need to make top-level names,
-- so we have a different entry point than for local bindings
rnTopBindsLHS :: MiniFixityEnv
              -> HsValBinds GhcPs
              -> RnM (HsValBindsLR GhcRn GhcPs)
rnTopBindsLHS :: MiniFixityEnv -> HsValBinds GhcPs -> RnM (HsValBindsLR GhcRn GhcPs)
rnTopBindsLHS MiniFixityEnv
fix_env HsValBinds GhcPs
binds
  = NameMaker -> HsValBinds GhcPs -> RnM (HsValBindsLR GhcRn GhcPs)
rnValBindsLHS (MiniFixityEnv -> NameMaker
topRecNameMaker MiniFixityEnv
fix_env) HsValBinds GhcPs
binds

-- Ensure that a hs-boot file has no top-level bindings.
rnTopBindsLHSBoot :: MiniFixityEnv
                  -> HsValBinds GhcPs
                  -> RnM (HsValBindsLR GhcRn GhcPs)
rnTopBindsLHSBoot :: MiniFixityEnv -> HsValBinds GhcPs -> RnM (HsValBindsLR GhcRn GhcPs)
rnTopBindsLHSBoot MiniFixityEnv
fix_env HsValBinds GhcPs
binds
  = do  { topBinds <- MiniFixityEnv -> HsValBinds GhcPs -> RnM (HsValBindsLR GhcRn GhcPs)
rnTopBindsLHS MiniFixityEnv
fix_env HsValBinds GhcPs
binds
        ; case topBinds of
            ValBinds XValBinds GhcRn GhcPs
x LHsBindsLR GhcRn GhcPs
mbinds [XRec GhcPs (Sig GhcPs)]
sigs ->
              do  { HsBootOrSig
-> (NonEmpty (LocatedA (HsBindLR GhcRn GhcPs)) -> BadBootDecls)
-> [LocatedA (HsBindLR GhcRn GhcPs)]
-> TcM ()
forall decl.
HsBootOrSig
-> (NonEmpty (LocatedA decl) -> BadBootDecls)
-> [LocatedA decl]
-> TcM ()
rejectBootDecls HsBootOrSig
HsBoot NonEmpty (LHsBindLR GhcRn GhcPs) -> BadBootDecls
NonEmpty (LocatedA (HsBindLR GhcRn GhcPs)) -> BadBootDecls
BootBindsPs LHsBindsLR GhcRn GhcPs
[LocatedA (HsBindLR GhcRn GhcPs)]
mbinds
                  ; HsValBindsLR GhcRn GhcPs -> RnM (HsValBindsLR GhcRn GhcPs)
forall a. a -> IOEnv (Env TcGblEnv TcLclEnv) a
forall (f :: * -> *) a. Applicative f => a -> f a
pure (XValBinds GhcRn GhcPs
-> LHsBindsLR GhcRn GhcPs
-> [XRec GhcPs (Sig GhcPs)]
-> HsValBindsLR GhcRn GhcPs
forall idL idR.
XValBinds idL idR
-> LHsBindsLR idL idR -> [LSig idR] -> HsValBindsLR idL idR
ValBinds XValBinds GhcRn GhcPs
x [] [XRec GhcPs (Sig GhcPs)]
sigs) }
            HsValBindsLR GhcRn GhcPs
_ -> String -> SDoc -> RnM (HsValBindsLR GhcRn GhcPs)
forall a. HasCallStack => String -> SDoc -> a
pprPanic String
"rnTopBindsLHSBoot" (HsValBindsLR GhcRn GhcPs -> SDoc
forall a. Outputable a => a -> SDoc
ppr HsValBindsLR GhcRn GhcPs
topBinds) }

rejectBootDecls :: HsBootOrSig
                -> (NonEmpty (LocatedA decl) -> BadBootDecls)
                -> [LocatedA decl]
                -> TcM ()
rejectBootDecls :: forall decl.
HsBootOrSig
-> (NonEmpty (LocatedA decl) -> BadBootDecls)
-> [LocatedA decl]
-> TcM ()
rejectBootDecls HsBootOrSig
_ NonEmpty (LocatedA decl) -> BadBootDecls
_ [] = () -> TcM ()
forall a. a -> IOEnv (Env TcGblEnv TcLclEnv) a
forall (m :: * -> *) a. Monad m => a -> m a
return ()
rejectBootDecls HsBootOrSig
hsc_src NonEmpty (LocatedA decl) -> BadBootDecls
what (decl :: LocatedA decl
decl@(L SrcSpanAnnA
loc decl
_) : [LocatedA decl]
decls)
  = SrcSpan -> TcRnMessage -> TcM ()
addErrAt (SrcSpanAnnA -> SrcSpan
forall a. HasLoc a => a -> SrcSpan
locA SrcSpanAnnA
loc)
  (TcRnMessage -> TcM ()) -> TcRnMessage -> TcM ()
forall a b. (a -> b) -> a -> b
$ HsBootOrSig -> BadBootDecls -> TcRnMessage
TcRnIllegalHsBootOrSigDecl HsBootOrSig
hsc_src
      (NonEmpty (LocatedA decl) -> BadBootDecls
what (NonEmpty (LocatedA decl) -> BadBootDecls)
-> NonEmpty (LocatedA decl) -> BadBootDecls
forall a b. (a -> b) -> a -> b
$ LocatedA decl
decl LocatedA decl -> [LocatedA decl] -> NonEmpty (LocatedA decl)
forall a. a -> [a] -> NonEmpty a
:| [LocatedA decl]
decls)

rnTopBindsBoot :: NameSet -> HsValBindsLR GhcRn GhcPs
               -> RnM (HsValBinds GhcRn, DefUses)
-- A hs-boot file has no bindings.
-- Return a single HsBindGroup with empty binds and renamed signatures
rnTopBindsBoot :: NameSet
-> HsValBindsLR GhcRn GhcPs -> RnM (HsValBinds GhcRn, DefUses)
rnTopBindsBoot NameSet
bound_names (ValBinds XValBinds GhcRn GhcPs
_ LHsBindsLR GhcRn GhcPs
_ [XRec GhcPs (Sig GhcPs)]
sigs)
  = do  { (sigs', fvs) <- HsSigCtxt
-> [XRec GhcPs (Sig GhcPs)] -> RnM ([LSig GhcRn], NameSet)
renameSigs (NameSet -> HsSigCtxt
HsBootCtxt NameSet
bound_names) [XRec GhcPs (Sig GhcPs)]
sigs
        ; return (XValBindsLR (NValBinds [] sigs'), usesOnly fvs) }
rnTopBindsBoot NameSet
_ HsValBindsLR GhcRn GhcPs
b = String -> SDoc -> RnM (HsValBinds GhcRn, DefUses)
forall a. HasCallStack => String -> SDoc -> a
pprPanic String
"rnTopBindsBoot" (HsValBindsLR GhcRn GhcPs -> SDoc
forall a. Outputable a => a -> SDoc
ppr HsValBindsLR GhcRn GhcPs
b)

{-
*********************************************************
*                                                      *
                HsLocalBinds
*                                                      *
*********************************************************
-}

rnLocalBindsAndThen :: HsLocalBinds GhcPs
                   -> (HsLocalBinds GhcRn -> FreeVars -> RnM (result, FreeVars))
                   -> RnM (result, FreeVars)
-- This version (a) assumes that the binding vars are *not* already in scope
--               (b) removes the binders from the free vars of the thing inside
-- The parser doesn't produce ThenBinds
rnLocalBindsAndThen :: forall result.
HsLocalBinds GhcPs
-> (HsLocalBinds GhcRn -> NameSet -> RnM (result, NameSet))
-> RnM (result, NameSet)
rnLocalBindsAndThen (EmptyLocalBinds XEmptyLocalBinds GhcPs GhcPs
x) HsLocalBinds GhcRn -> NameSet -> RnM (result, NameSet)
thing_inside =
  HsLocalBinds GhcRn -> NameSet -> RnM (result, NameSet)
thing_inside (XEmptyLocalBinds GhcRn GhcRn -> HsLocalBinds GhcRn
forall idL idR. XEmptyLocalBinds idL idR -> HsLocalBindsLR idL idR
EmptyLocalBinds XEmptyLocalBinds GhcPs GhcPs
XEmptyLocalBinds GhcRn GhcRn
x) NameSet
emptyNameSet

rnLocalBindsAndThen (HsValBinds XHsValBinds GhcPs GhcPs
x HsValBinds GhcPs
val_binds) HsLocalBinds GhcRn -> NameSet -> RnM (result, NameSet)
thing_inside
  = HsValBinds GhcPs
-> (HsValBinds GhcRn -> NameSet -> RnM (result, NameSet))
-> RnM (result, NameSet)
forall result.
HsValBinds GhcPs
-> (HsValBinds GhcRn -> NameSet -> RnM (result, NameSet))
-> RnM (result, NameSet)
rnLocalValBindsAndThen HsValBinds GhcPs
val_binds ((HsValBinds GhcRn -> NameSet -> RnM (result, NameSet))
 -> RnM (result, NameSet))
-> (HsValBinds GhcRn -> NameSet -> RnM (result, NameSet))
-> RnM (result, NameSet)
forall a b. (a -> b) -> a -> b
$ \ HsValBinds GhcRn
val_binds' ->
      HsLocalBinds GhcRn -> NameSet -> RnM (result, NameSet)
thing_inside (XHsValBinds GhcRn GhcRn -> HsValBinds GhcRn -> HsLocalBinds GhcRn
forall idL idR.
XHsValBinds idL idR
-> HsValBindsLR idL idR -> HsLocalBindsLR idL idR
HsValBinds XHsValBinds GhcPs GhcPs
XHsValBinds GhcRn GhcRn
x HsValBinds GhcRn
val_binds')

rnLocalBindsAndThen (HsIPBinds XHsIPBinds GhcPs GhcPs
x HsIPBinds GhcPs
binds) HsLocalBinds GhcRn -> NameSet -> RnM (result, NameSet)
thing_inside = do
    (binds',fv_binds) <- HsIPBinds GhcPs -> RnM (HsIPBinds GhcRn, NameSet)
rnIPBinds HsIPBinds GhcPs
binds
    (thing, fvs_thing) <- thing_inside (HsIPBinds x binds') fv_binds
    return (thing, fvs_thing `plusFV` fv_binds)

rnIPBinds :: HsIPBinds GhcPs -> RnM (HsIPBinds GhcRn, FreeVars)
rnIPBinds :: HsIPBinds GhcPs -> RnM (HsIPBinds GhcRn, NameSet)
rnIPBinds (IPBinds XIPBinds GhcPs
_ [LIPBind GhcPs]
ip_binds ) = do
    (ip_binds', fvs_s) <- (GenLocated SrcSpanAnnA (IPBind GhcPs)
 -> IOEnv
      (Env TcGblEnv TcLclEnv)
      (GenLocated SrcSpanAnnA (IPBind GhcRn), NameSet))
-> [GenLocated SrcSpanAnnA (IPBind GhcPs)]
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     ([GenLocated SrcSpanAnnA (IPBind GhcRn)], [NameSet])
forall (m :: * -> *) a b c.
Applicative m =>
(a -> m (b, c)) -> [a] -> m ([b], [c])
mapAndUnzipM ((IPBind GhcPs -> TcM (IPBind GhcRn, NameSet))
-> GenLocated SrcSpanAnnA (IPBind GhcPs)
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     (GenLocated SrcSpanAnnA (IPBind GhcRn), NameSet)
forall a b c ann.
(a -> TcM (b, c))
-> GenLocated (EpAnn ann) a -> TcM (GenLocated (EpAnn ann) b, c)
wrapLocFstMA IPBind GhcPs -> TcM (IPBind GhcRn, NameSet)
rnIPBind) [LIPBind GhcPs]
[GenLocated SrcSpanAnnA (IPBind GhcPs)]
ip_binds
    return (IPBinds noExtField ip_binds', plusFVs fvs_s)

rnIPBind :: IPBind GhcPs -> RnM (IPBind GhcRn, FreeVars)
rnIPBind :: IPBind GhcPs -> TcM (IPBind GhcRn, NameSet)
rnIPBind (IPBind XCIPBind GhcPs
_ XRec GhcPs HsIPName
n LHsExpr GhcPs
expr) = do
    (expr',fvExpr) <- LHsExpr GhcPs -> RnM (LHsExpr GhcRn, NameSet)
rnLExpr LHsExpr GhcPs
expr
    return (IPBind noExtField n expr', fvExpr)

{-
************************************************************************
*                                                                      *
                ValBinds
*                                                                      *
************************************************************************
-}

-- Renaming local binding groups
-- Does duplicate/shadow check
rnLocalValBindsLHS :: MiniFixityEnv
                   -> HsValBinds GhcPs
                   -> RnM ([Name], HsValBindsLR GhcRn GhcPs)
rnLocalValBindsLHS :: MiniFixityEnv
-> HsValBinds GhcPs -> RnM ([Name], HsValBindsLR GhcRn GhcPs)
rnLocalValBindsLHS MiniFixityEnv
fix_env HsValBinds GhcPs
binds
  = do { binds' <- NameMaker -> HsValBinds GhcPs -> RnM (HsValBindsLR GhcRn GhcPs)
rnValBindsLHS (MiniFixityEnv -> NameMaker
localRecNameMaker MiniFixityEnv
fix_env) HsValBinds GhcPs
binds

         -- Check for duplicates and shadowing
         -- Must do this *after* renaming the patterns
         -- See Note [Collect binders only after renaming] in GHC.Hs.Utils

         -- We need to check for dups here because we
         -- don't don't bind all of the variables from the ValBinds at once
         -- with bindLocatedLocals any more.
         --
         -- Note that we don't want to do this at the top level, since
         -- sorting out duplicates and shadowing there happens elsewhere.
         -- The behavior is even different. For example,
         --   import A(f)
         --   f = ...
         -- should not produce a shadowing warning (but it will produce
         -- an ambiguity warning if you use f), but
         --   import A(f)
         --   g = let f = ... in f
         -- should.
       ; let bound_names = CollectFlag GhcRn -> HsValBindsLR GhcRn GhcPs -> [IdP GhcRn]
forall (idL :: Pass) idR.
CollectPass (GhcPass idL) =>
CollectFlag (GhcPass idL)
-> HsValBindsLR (GhcPass idL) idR -> [IdP (GhcPass idL)]
collectHsValBinders CollectFlag GhcRn
forall p. CollectFlag p
CollNoDictBinders HsValBindsLR GhcRn GhcPs
binds'
             -- There should be only Ids, but if there are any bogus
             -- pattern synonyms, we'll collect them anyway, so that
             -- we don't generate subsequent out-of-scope messages
       ; envs <- getRdrEnvs
       ; checkDupAndShadowedNames envs bound_names

       ; return (bound_names, binds') }

-- renames the left-hand sides
-- generic version used both at the top level and for local binds
-- does some error checking, but not what gets done elsewhere at the top level
rnValBindsLHS :: NameMaker
              -> HsValBinds GhcPs
              -> RnM (HsValBindsLR GhcRn GhcPs)
rnValBindsLHS :: NameMaker -> HsValBinds GhcPs -> RnM (HsValBindsLR GhcRn GhcPs)
rnValBindsLHS NameMaker
topP (ValBinds XValBinds GhcPs GhcPs
x LHsBindsLR GhcPs GhcPs
mbinds [XRec GhcPs (Sig GhcPs)]
sigs)
  = do { mbinds' <- (GenLocated SrcSpanAnnA (HsBind GhcPs)
 -> IOEnv (Env TcGblEnv TcLclEnv) (LocatedA (HsBindLR GhcRn GhcPs)))
-> [GenLocated SrcSpanAnnA (HsBind GhcPs)]
-> IOEnv (Env TcGblEnv TcLclEnv) [LocatedA (HsBindLR GhcRn GhcPs)]
forall (t :: * -> *) (m :: * -> *) a b.
(Traversable t, Monad m) =>
(a -> m b) -> t a -> m (t b)
forall (m :: * -> *) a b. Monad m => (a -> m b) -> [a] -> m [b]
mapM ((HsBind GhcPs -> TcM (HsBindLR GhcRn GhcPs))
-> GenLocated SrcSpanAnnA (HsBind GhcPs)
-> IOEnv (Env TcGblEnv TcLclEnv) (LocatedA (HsBindLR GhcRn GhcPs))
forall a b ann.
(a -> TcM b)
-> GenLocated (EpAnn ann) a -> TcRn (GenLocated (EpAnn ann) b)
wrapLocMA (NameMaker -> SDoc -> HsBind GhcPs -> TcM (HsBindLR GhcRn GhcPs)
rnBindLHS NameMaker
topP SDoc
doc)) LHsBindsLR GhcPs GhcPs
[GenLocated SrcSpanAnnA (HsBind GhcPs)]
mbinds
       ; return $ ValBinds x mbinds' sigs }
  where
    bndrs :: [IdP GhcPs]
bndrs = CollectFlag GhcPs -> LHsBindsLR GhcPs GhcPs -> [IdP GhcPs]
forall p idR.
CollectPass p =>
CollectFlag p -> LHsBindsLR p idR -> [IdP p]
collectHsBindsBinders CollectFlag GhcPs
forall p. CollectFlag p
CollNoDictBinders LHsBindsLR GhcPs GhcPs
mbinds
    doc :: SDoc
doc   = String -> SDoc
forall doc. IsLine doc => String -> doc
text String
"In the binding group for:" SDoc -> SDoc -> SDoc
forall doc. IsLine doc => doc -> doc -> doc
<+> (RdrName -> SDoc) -> [RdrName] -> SDoc
forall a. (a -> SDoc) -> [a] -> SDoc
pprWithCommas RdrName -> SDoc
forall a. Outputable a => a -> SDoc
ppr [IdP GhcPs]
[RdrName]
bndrs

rnValBindsLHS NameMaker
_ HsValBinds GhcPs
b = String -> SDoc -> RnM (HsValBindsLR GhcRn GhcPs)
forall a. HasCallStack => String -> SDoc -> a
pprPanic String
"rnValBindsLHSFromDoc" (HsValBinds GhcPs -> SDoc
forall a. Outputable a => a -> SDoc
ppr HsValBinds GhcPs
b)

-- General version used both from the top-level and for local things
-- Assumes the LHS vars are in scope
--
-- Does not bind the local fixity declarations
rnValBindsRHS :: HsSigCtxt
              -> HsValBindsLR GhcRn GhcPs
              -> RnM (HsValBinds GhcRn, DefUses)

rnValBindsRHS :: HsSigCtxt
-> HsValBindsLR GhcRn GhcPs -> RnM (HsValBinds GhcRn, DefUses)
rnValBindsRHS HsSigCtxt
ctxt (ValBinds XValBinds GhcRn GhcPs
_ LHsBindsLR GhcRn GhcPs
mbinds [XRec GhcPs (Sig GhcPs)]
sigs)
  = do { (sigs', sig_fvs) <- HsSigCtxt
-> [XRec GhcPs (Sig GhcPs)] -> RnM ([LSig GhcRn], NameSet)
renameSigs HsSigCtxt
ctxt [XRec GhcPs (Sig GhcPs)]
sigs

       -- Update the TcGblEnv with renamed COMPLETE pragmas from the current
       -- module, for pattern irrefutability checking in do notation.
       ; let localCompletePrags = [LSig GhcRn] -> CompleteMatches
localCompletePragmas [LSig GhcRn]
[GenLocated SrcSpanAnnA (Sig GhcRn)]
sigs'
       ; updGblEnv (\TcGblEnv
gblEnv -> TcGblEnv
gblEnv { tcg_complete_matches = tcg_complete_matches gblEnv ++ localCompletePrags}) $
    do { binds_w_dus <- mapM (rnLBind (mkScopedTvFn sigs')) mbinds
       ; let !(anal_binds, anal_dus) = depAnalBinds binds_w_dus

       ; let patsyn_fvs = (PatSynBind GhcRn GhcRn -> NameSet -> NameSet)
-> NameSet -> [PatSynBind GhcRn GhcRn] -> NameSet
forall a b. (a -> b -> b) -> b -> [a] -> b
forall (t :: * -> *) a b.
Foldable t =>
(a -> b -> b) -> b -> t a -> b
foldr (NameSet -> NameSet -> NameSet
unionNameSet (NameSet -> NameSet -> NameSet)
-> (PatSynBind GhcRn GhcRn -> NameSet)
-> PatSynBind GhcRn GhcRn
-> NameSet
-> NameSet
forall b c a. (b -> c) -> (a -> b) -> a -> c
. PatSynBind GhcRn GhcRn -> XPSB GhcRn GhcRn
PatSynBind GhcRn GhcRn -> NameSet
forall idL idR. PatSynBind idL idR -> XPSB idL idR
psb_ext) NameSet
emptyNameSet ([PatSynBind GhcRn GhcRn] -> NameSet)
-> [PatSynBind GhcRn GhcRn] -> NameSet
forall a b. (a -> b) -> a -> b
$
                          [(RecFlag, LHsBinds GhcRn)] -> [PatSynBind GhcRn GhcRn]
forall id.
UnXRec id =>
[(RecFlag, LHsBinds id)] -> [PatSynBind id id]
getPatSynBinds [(RecFlag, LHsBinds GhcRn)]
anal_binds
                -- The uses in binds_w_dus for PatSynBinds do not include
                -- variables used in the patsyn builders; see
                -- Note [Pattern synonym builders don't yield dependencies]
                -- But psb_fvs /does/ include those builder fvs.  So we
                -- add them back in here to avoid bogus warnings about
                -- unused variables (#12548)

             valbind'_dus = DefUses
anal_dus DefUses -> DefUses -> DefUses
`plusDU` NameSet -> DefUses
usesOnly NameSet
sig_fvs
                                     DefUses -> DefUses -> DefUses
`plusDU` NameSet -> DefUses
usesOnly NameSet
patsyn_fvs
                            -- Put the sig uses *after* the bindings
                            -- so that the binders are removed from
                            -- the uses in the sigs

        ; return (XValBindsLR (NValBinds anal_binds sigs'), valbind'_dus) } }

rnValBindsRHS HsSigCtxt
_ HsValBindsLR GhcRn GhcPs
b = String -> SDoc -> RnM (HsValBinds GhcRn, DefUses)
forall a. HasCallStack => String -> SDoc -> a
pprPanic String
"rnValBindsRHS" (HsValBindsLR GhcRn GhcPs -> SDoc
forall a. Outputable a => a -> SDoc
ppr HsValBindsLR GhcRn GhcPs
b)

-- Wrapper for local binds
--
-- The *client* of this function is responsible for checking for unused binders;
-- it doesn't (and can't: we don't have the thing inside the binds) happen here
--
-- The client is also responsible for bringing the fixities into scope
rnLocalValBindsRHS :: NameSet  -- names bound by the LHSes
                   -> HsValBindsLR GhcRn GhcPs
                   -> RnM (HsValBinds GhcRn, DefUses)
rnLocalValBindsRHS :: NameSet
-> HsValBindsLR GhcRn GhcPs -> RnM (HsValBinds GhcRn, DefUses)
rnLocalValBindsRHS NameSet
bound_names HsValBindsLR GhcRn GhcPs
binds
  = HsSigCtxt
-> HsValBindsLR GhcRn GhcPs -> RnM (HsValBinds GhcRn, DefUses)
rnValBindsRHS (NameSet -> HsSigCtxt
LocalBindCtxt NameSet
bound_names) HsValBindsLR GhcRn GhcPs
binds

-- for local binds
-- wrapper that does both the left- and right-hand sides
--
-- here there are no local fixity decls passed in;
-- the local fixity decls come from the ValBinds sigs
rnLocalValBindsAndThen
  :: HsValBinds GhcPs
  -> (HsValBinds GhcRn -> FreeVars -> RnM (result, FreeVars))
  -> RnM (result, FreeVars)
rnLocalValBindsAndThen :: forall result.
HsValBinds GhcPs
-> (HsValBinds GhcRn -> NameSet -> RnM (result, NameSet))
-> RnM (result, NameSet)
rnLocalValBindsAndThen binds :: HsValBinds GhcPs
binds@(ValBinds XValBinds GhcPs GhcPs
_ LHsBindsLR GhcPs GhcPs
_ [XRec GhcPs (Sig GhcPs)]
sigs) HsValBinds GhcRn -> NameSet -> RnM (result, NameSet)
thing_inside
 = do   {     -- (A) Create the local fixity environment
          new_fixities <- [LFixitySig GhcPs] -> RnM MiniFixityEnv
makeMiniFixityEnv [ SrcSpanAnnA
-> FixitySig GhcPs -> GenLocated SrcSpanAnnA (FixitySig GhcPs)
forall l e. l -> e -> GenLocated l e
L SrcSpanAnnA
loc FixitySig GhcPs
sig
                                            | L SrcSpanAnnA
loc (FixSig XFixSig GhcPs
_ FixitySig GhcPs
sig) <- [XRec GhcPs (Sig GhcPs)]
[GenLocated SrcSpanAnnA (Sig GhcPs)]
sigs]

              -- (B) Rename the LHSes
        ; (bound_names, new_lhs) <- rnLocalValBindsLHS new_fixities binds

              --     ...and bring them (and their fixities) into scope
        ; bindLocalNamesFV bound_names              $
          addLocalFixities new_fixities bound_names $ do

        {      -- (C) Do the RHS and thing inside
          (binds', dus) <- rnLocalValBindsRHS (mkNameSet bound_names) new_lhs
        ; (result, result_fvs) <- thing_inside binds' (allUses dus)

                -- Report unused bindings based on the (accurate)
                -- findUses.  E.g.
                --      let x = x in 3
                -- should report 'x' unused
        ; let real_uses = DefUses -> NameSet -> NameSet
findUses DefUses
dus NameSet
result_fvs
              -- Insert fake uses for variables introduced implicitly by
              -- wildcards (#4404)
              rec_uses = HsValBinds GhcRn -> [(SrcSpan, [ImplicitFieldBinders])]
forall (idR :: Pass).
HsValBindsLR GhcRn (GhcPass idR)
-> [(SrcSpan, [ImplicitFieldBinders])]
hsValBindsImplicits HsValBinds GhcRn
binds'
              implicit_uses = [Name] -> NameSet
mkNameSet ([Name] -> NameSet) -> [Name] -> NameSet
forall a b. (a -> b) -> a -> b
$ ((SrcSpan, [ImplicitFieldBinders]) -> [Name])
-> [(SrcSpan, [ImplicitFieldBinders])] -> [Name]
forall (t :: * -> *) a b. Foldable t => (a -> [b]) -> t a -> [b]
concatMap ((ImplicitFieldBinders -> [Name])
-> [ImplicitFieldBinders] -> [Name]
forall (t :: * -> *) a b. Foldable t => (a -> [b]) -> t a -> [b]
concatMap ImplicitFieldBinders -> [Name]
implFlBndr_binders ([ImplicitFieldBinders] -> [Name])
-> ((SrcSpan, [ImplicitFieldBinders]) -> [ImplicitFieldBinders])
-> (SrcSpan, [ImplicitFieldBinders])
-> [Name]
forall b c a. (b -> c) -> (a -> b) -> a -> c
. (SrcSpan, [ImplicitFieldBinders]) -> [ImplicitFieldBinders]
forall a b. (a, b) -> b
snd)
                                        ([(SrcSpan, [ImplicitFieldBinders])] -> [Name])
-> [(SrcSpan, [ImplicitFieldBinders])] -> [Name]
forall a b. (a -> b) -> a -> b
$ [(SrcSpan, [ImplicitFieldBinders])]
rec_uses
        ; mapM_ (\(SrcSpan
loc, [ImplicitFieldBinders]
ns) ->
                    SrcSpan -> NameSet -> Maybe [ImplicitFieldBinders] -> TcM ()
checkUnusedRecordWildcard SrcSpan
loc NameSet
real_uses ([ImplicitFieldBinders] -> Maybe [ImplicitFieldBinders]
forall a. a -> Maybe a
Just [ImplicitFieldBinders]
ns))
                rec_uses
        ; warnUnusedLocalBinds bound_names
                                      (real_uses `unionNameSet` implicit_uses)

        ; let
            -- The variables "used" in the val binds are:
            --   (1) the uses of the binds (allUses)
            --   (2) the FVs of the thing-inside
            all_uses = DefUses -> NameSet
allUses DefUses
dus NameSet -> NameSet -> NameSet
`plusFV` NameSet
result_fvs
                -- Note [Unused binding hack]
                -- ~~~~~~~~~~~~~~~~~~~~~~~~~~
                -- Note that *in contrast* to the above reporting of
                -- unused bindings, (1) above uses duUses to return *all*
                -- the uses, even if the binding is unused.  Otherwise consider:
                --      x = 3
                --      y = let p = x in 'x'    -- NB: p not used
                -- If we don't "see" the dependency of 'y' on 'x', we may put the
                -- bindings in the wrong order, and the type checker will complain
                -- that x isn't in scope
                --
                -- But note that this means we won't report 'x' as unused,
                -- whereas we would if we had { x = 3; p = x; y = 'x' }

        ; return (result, all_uses) }}
                -- The bound names are pruned out of all_uses
                -- by the bindLocalNamesFV call above

rnLocalValBindsAndThen HsValBinds GhcPs
bs HsValBinds GhcRn -> NameSet -> RnM (result, NameSet)
_ = String -> SDoc -> RnM (result, NameSet)
forall a. HasCallStack => String -> SDoc -> a
pprPanic String
"rnLocalValBindsAndThen" (HsValBinds GhcPs -> SDoc
forall a. Outputable a => a -> SDoc
ppr HsValBinds GhcPs
bs)


---------------------

-- renaming a single bind

rnBindLHS :: NameMaker
          -> SDoc
          -> HsBind GhcPs
          -- returns the renamed left-hand side,
          -- and the FreeVars *of the LHS*
          -- (i.e., any free variables of the pattern)
          -> RnM (HsBindLR GhcRn GhcPs)

rnBindLHS :: NameMaker -> SDoc -> HsBind GhcPs -> TcM (HsBindLR GhcRn GhcPs)
rnBindLHS NameMaker
name_maker SDoc
_ bind :: HsBind GhcPs
bind@(PatBind { pat_lhs :: forall idL idR. HsBindLR idL idR -> LPat idL
pat_lhs = LPat GhcPs
pat, pat_mult :: forall idL idR. HsBindLR idL idR -> HsMultAnn idL
pat_mult = HsMultAnn GhcPs
pat_mult })
  = do
      -- we don't actually use the FV processing of rnPatsAndThen here
      (pat',pat'_fvs) <- NameMaker -> LPat GhcPs -> RnM (LPat GhcRn, NameSet)
rnBindPat NameMaker
name_maker LPat GhcPs
pat
      (pat_mult', mult'_fvs) <- rnHsMultAnn pat_mult
      return (bind { pat_lhs = pat', pat_ext = pat'_fvs `plusFV` mult'_fvs, pat_mult = pat_mult' })
                -- We temporarily store the pat's FVs in bind_fvs;
                -- gets updated to the FVs of the whole bind
                -- when doing the RHS below

rnBindLHS NameMaker
name_maker SDoc
_ bind :: HsBind GhcPs
bind@(FunBind { fun_id :: forall idL idR. HsBindLR idL idR -> LIdP idL
fun_id = LIdP GhcPs
rdr_name })
  = do { name <- NameMaker -> LocatedN RdrName -> RnM (GenLocated SrcSpanAnnN Name)
applyNameMaker NameMaker
name_maker LIdP GhcPs
LocatedN RdrName
rdr_name
       ; return (bind { fun_id = name
                      , fun_ext = noExtField }) }

rnBindLHS NameMaker
name_maker SDoc
_ (PatSynBind XPatSynBind GhcPs GhcPs
x psb :: PatSynBind GhcPs GhcPs
psb@PSB{ psb_id :: forall idL idR. PatSynBind idL idR -> LIdP idL
psb_id = LIdP GhcPs
rdrname })
  | NameMaker -> Bool
isTopRecNameMaker NameMaker
name_maker
  = do { (RdrName -> TcM ()) -> LocatedN RdrName -> TcM ()
forall t a b. HasLoc t => (a -> TcM b) -> GenLocated t a -> TcM b
addLocM RdrName -> TcM ()
checkConName LIdP GhcPs
LocatedN RdrName
rdrname
       ; name <-
           LocatedN RdrName -> RnM (GenLocated SrcSpanAnnN Name)
lookupLocatedTopConstructorRnN LIdP GhcPs
LocatedN RdrName
rdrname -- Should be in scope already
       ; return (PatSynBind x psb{ psb_ext = noAnn, psb_id = name }) }

  | Bool
otherwise  -- Pattern synonym, not at top level
  = do { TcRnMessage -> TcM ()
addErr TcRnMessage
localPatternSynonymErr  -- Complain, but make up a fake
                                        -- name so that we can carry on
       ; name <- NameMaker -> LocatedN RdrName -> RnM (GenLocated SrcSpanAnnN Name)
applyNameMaker NameMaker
name_maker LIdP GhcPs
LocatedN RdrName
rdrname
       ; return (PatSynBind x psb{ psb_ext = noAnn, psb_id = name }) }
  where
    localPatternSynonymErr :: TcRnMessage
    localPatternSynonymErr :: TcRnMessage
localPatternSynonymErr = LIdP GhcPs -> TcRnMessage
TcRnIllegalPatSynDecl LIdP GhcPs
rdrname

rnBindLHS NameMaker
_ SDoc
_ HsBind GhcPs
b = String -> SDoc -> TcM (HsBindLR GhcRn GhcPs)
forall a. HasCallStack => String -> SDoc -> a
pprPanic String
"rnBindHS" (HsBind GhcPs -> SDoc
forall a. Outputable a => a -> SDoc
ppr HsBind GhcPs
b)

rnLBind :: (Name -> [Name])      -- Signature tyvar function
        -> LHsBindLR GhcRn GhcPs
        -> RnM (LHsBind GhcRn, [Name], Uses)
rnLBind :: (Name -> [Name])
-> LHsBindLR GhcRn GhcPs -> RnM (LHsBind GhcRn, [Name], NameSet)
rnLBind Name -> [Name]
sig_fn (L SrcSpanAnnA
loc HsBindLR GhcRn GhcPs
bind)
  = SrcSpanAnnA
-> RnM (LHsBind GhcRn, [Name], NameSet)
-> RnM (LHsBind GhcRn, [Name], NameSet)
forall ann a. EpAnn ann -> TcRn a -> TcRn a
setSrcSpanA SrcSpanAnnA
loc (RnM (LHsBind GhcRn, [Name], NameSet)
 -> RnM (LHsBind GhcRn, [Name], NameSet))
-> RnM (LHsBind GhcRn, [Name], NameSet)
-> RnM (LHsBind GhcRn, [Name], NameSet)
forall a b. (a -> b) -> a -> b
$
    do { (bind', bndrs, dus) <- (Name -> [Name])
-> HsBindLR GhcRn GhcPs
-> RnM (HsBindLR GhcRn GhcRn, [Name], NameSet)
rnBind Name -> [Name]
sig_fn HsBindLR GhcRn GhcPs
bind
       ; return (L loc bind', bndrs, dus) }

-- assumes the left-hands-side vars are in scope
rnBind :: (Name -> [Name])        -- Signature tyvar function
       -> HsBindLR GhcRn GhcPs
       -> RnM (HsBind GhcRn, [Name], Uses)
rnBind :: (Name -> [Name])
-> HsBindLR GhcRn GhcPs
-> RnM (HsBindLR GhcRn GhcRn, [Name], NameSet)
rnBind Name -> [Name]
_ bind :: HsBindLR GhcRn GhcPs
bind@(PatBind { pat_lhs :: forall idL idR. HsBindLR idL idR -> LPat idL
pat_lhs = LPat GhcRn
pat
                       , pat_rhs :: forall idL idR. HsBindLR idL idR -> GRHSs idR (LHsExpr idR)
pat_rhs = GRHSs GhcPs (LHsExpr GhcPs)
grhss
                                   -- pat fvs were stored in bind_fvs
                                   -- after processing the LHS
                       , pat_ext :: forall idL idR. HsBindLR idL idR -> XPatBind idL idR
pat_ext = XPatBind GhcRn GhcPs
pat_fvs })
  = do  { mod <- IOEnv (Env TcGblEnv TcLclEnv) Module
forall (m :: * -> *). HasModule m => m Module
getModule
        ; (grhss', rhs_fvs) <- rnGRHSs PatBindRhs rnLExpr grhss

                -- No scoped type variables for pattern bindings
        ; let all_fvs = XPatBind GhcRn GhcPs
NameSet
pat_fvs NameSet -> NameSet -> NameSet
`plusFV` NameSet
rhs_fvs
              fvs'    = (Name -> Bool) -> NameSet -> NameSet
filterNameSet (Module -> Name -> Bool
nameIsLocalOrFrom Module
mod) NameSet
all_fvs
                -- Keep locally-defined Names
                -- As well as dependency analysis, we need these for the
                -- MonoLocalBinds test in GHC.Tc.Gen.Bind.decideGeneralisationPlan
              bndrs = CollectFlag GhcRn -> LPat GhcRn -> [IdP GhcRn]
forall p. CollectPass p => CollectFlag p -> LPat p -> [IdP p]
collectPatBinders CollectFlag GhcRn
forall p. CollectFlag p
CollNoDictBinders LPat GhcRn
pat
              bind' = HsBindLR GhcRn GhcPs
bind { pat_rhs  = grhss'
                           , pat_ext = fvs' }

        -- Warn if the pattern binds no variables
        -- See Note [Pattern bindings that bind no variables]
        ; whenWOptM Opt_WarnUnusedPatternBinds $
          when (null bndrs && not (isOkNoBindPattern pat)) $
          addTcRnDiagnostic (TcRnUnusedPatternBinds bind')

        ; fvs' `seq` -- See Note [Free-variable space leak]
          return (bind', bndrs, all_fvs) }

rnBind Name -> [Name]
sig_fn bind :: HsBindLR GhcRn GhcPs
bind@(FunBind { fun_id :: forall idL idR. HsBindLR idL idR -> LIdP idL
fun_id = XRec GhcRn (IdP GhcRn)
name
                            , fun_matches :: forall idL idR. HsBindLR idL idR -> MatchGroup idR (LHsExpr idR)
fun_matches = MatchGroup GhcPs (LHsExpr GhcPs)
matches })
       -- invariant: no free vars here when it's a FunBind
  = do  { let plain_name :: Name
plain_name = GenLocated SrcSpanAnnN Name -> Name
forall l e. GenLocated l e -> e
unLoc XRec GhcRn (IdP GhcRn)
GenLocated SrcSpanAnnN Name
name

        ; (matches', rhs_fvs) <- [Name]
-> RnM
     (MatchGroup GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn)), NameSet)
-> RnM
     (MatchGroup GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn)), NameSet)
forall a. [Name] -> RnM (a, NameSet) -> RnM (a, NameSet)
bindSigTyVarsFV (Name -> [Name]
sig_fn Name
plain_name) (RnM
   (MatchGroup GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn)), NameSet)
 -> RnM
      (MatchGroup GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn)),
       NameSet))
-> RnM
     (MatchGroup GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn)), NameSet)
-> RnM
     (MatchGroup GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn)), NameSet)
forall a b. (a -> b) -> a -> b
$
                                -- bindSigTyVars tests for LangExt.ScopedTyVars
                                 HsMatchContextRn
-> (LocatedA (HsExpr GhcPs)
    -> IOEnv
         (Env TcGblEnv TcLclEnv)
         (GenLocated SrcSpanAnnA (HsExpr GhcRn), NameSet))
-> MatchGroup GhcPs (LocatedA (HsExpr GhcPs))
-> RnM
     (MatchGroup GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn)), NameSet)
forall (body :: * -> *).
(Outputable (body GhcPs), AnnoBody body) =>
HsMatchContextRn
-> (LocatedA (body GhcPs) -> RnM (LocatedA (body GhcRn), NameSet))
-> MatchGroup GhcPs (LocatedA (body GhcPs))
-> RnM (MatchGroup GhcRn (LocatedA (body GhcRn)), NameSet)
rnMatchGroup (GenLocated SrcSpanAnnN Name
-> AnnFunRhs -> HsMatchContext (GenLocated SrcSpanAnnN Name)
forall fn. fn -> AnnFunRhs -> HsMatchContext fn
mkPrefixFunRhs XRec GhcRn (IdP GhcRn)
GenLocated SrcSpanAnnN Name
name AnnFunRhs
forall a. NoAnn a => a
noAnn)
                                              LHsExpr GhcPs -> RnM (LHsExpr GhcRn, NameSet)
LocatedA (HsExpr GhcPs)
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     (GenLocated SrcSpanAnnA (HsExpr GhcRn), NameSet)
rnLExpr MatchGroup GhcPs (LHsExpr GhcPs)
MatchGroup GhcPs (LocatedA (HsExpr GhcPs))
matches
        ; let is_infix = HsBindLR GhcRn GhcPs -> Bool
forall id1 id2. UnXRec id2 => HsBindLR id1 id2 -> Bool
isInfixFunBind HsBindLR GhcRn GhcPs
bind
        ; when is_infix $ checkPrecMatch plain_name matches'

        ; mod <- getModule
        ; let fvs' = (Name -> Bool) -> NameSet -> NameSet
filterNameSet (Module -> Name -> Bool
nameIsLocalOrFrom Module
mod) NameSet
rhs_fvs
                -- Keep locally-defined Names
                -- As well as dependency analysis, we need these for the
                -- MonoLocalBinds test in GHC.Tc.Gen.Bind.decideGeneralisationPlan

        ; fvs' `seq` -- See Note [Free-variable space leak]
          return (bind { fun_matches = matches'
                       , fun_ext     = fvs' },
                  [plain_name], rhs_fvs)
      }

rnBind Name -> [Name]
sig_fn (PatSynBind XPatSynBind GhcRn GhcPs
x PatSynBind GhcRn GhcPs
bind)
  = do  { (bind', name, fvs) <- (Name -> [Name])
-> PatSynBind GhcRn GhcPs
-> RnM (PatSynBind GhcRn GhcRn, [Name], NameSet)
rnPatSynBind Name -> [Name]
sig_fn PatSynBind GhcRn GhcPs
bind
        ; return (PatSynBind x bind', name, fvs) }

rnBind Name -> [Name]
_ (VarBind { var_ext :: forall idL idR. HsBindLR idL idR -> XVarBind idL idR
var_ext = XVarBind GhcRn GhcPs
x }) = DataConCantHappen -> RnM (HsBindLR GhcRn GhcRn, [Name], NameSet)
forall a. DataConCantHappen -> a
dataConCantHappen XVarBind GhcRn GhcPs
DataConCantHappen
x

 -- See Note [Pattern bindings that bind no variables]
isOkNoBindPattern :: LPat GhcRn -> Bool
isOkNoBindPattern :: LPat GhcRn -> Bool
isOkNoBindPattern (L SrcSpanAnnA
_ Pat GhcRn
pat) =
  case Pat GhcRn
pat of
    WildPat{}       -> Bool
True -- Exception (1)
    BangPat {}      -> Bool
True -- Exception (2) #9127, #13646
    Pat GhcRn
p -> Pat GhcRn -> Bool
patternContainsSplice Pat GhcRn
p -- Exception (3)

    where
      lpatternContainsSplice :: LPat GhcRn -> Bool
      lpatternContainsSplice :: LPat GhcRn -> Bool
lpatternContainsSplice (L SrcSpanAnnA
_ Pat GhcRn
p) = Pat GhcRn -> Bool
patternContainsSplice Pat GhcRn
p
      patternContainsSplice :: Pat GhcRn -> Bool
      patternContainsSplice :: Pat GhcRn -> Bool
patternContainsSplice Pat GhcRn
p =
        case Pat GhcRn
p of
          -- A top-level splice has been evaluated by this point, so we know the pattern it is evaluated to
          SplicePat (HsUntypedSpliceTop ThModFinalizers
_ Pat GhcRn
p) HsUntypedSplice GhcRn
_ -> Pat GhcRn -> Bool
patternContainsSplice Pat GhcRn
p
          -- A nested splice isn't evaluated so we can't guess what it will expand to
          SplicePat (HsUntypedSpliceNested {}) HsUntypedSplice GhcRn
_ -> Bool
True
          -- The base cases
          VarPat {} -> Bool
False
          WildPat {} -> Bool
False
          LitPat {} -> Bool
False
          NPat {} -> Bool
False
          NPlusKPat {} -> Bool
False
          -- Recursive cases
          BangPat XBangPat GhcRn
_ LPat GhcRn
lp -> LPat GhcRn -> Bool
lpatternContainsSplice LPat GhcRn
lp
          LazyPat XLazyPat GhcRn
_ LPat GhcRn
lp -> LPat GhcRn -> Bool
lpatternContainsSplice LPat GhcRn
lp
          AsPat XAsPat GhcRn
_ XRec GhcRn (IdP GhcRn)
_ LPat GhcRn
lp  -> LPat GhcRn -> Bool
lpatternContainsSplice LPat GhcRn
lp
          ParPat XParPat GhcRn
_ LPat GhcRn
lp -> LPat GhcRn -> Bool
lpatternContainsSplice LPat GhcRn
lp
          ViewPat XViewPat GhcRn
_ LHsExpr GhcRn
_ LPat GhcRn
lp -> LPat GhcRn -> Bool
lpatternContainsSplice LPat GhcRn
lp
          OrPat XOrPat GhcRn
_ NonEmpty (LPat GhcRn)
lps -> (GenLocated SrcSpanAnnA (Pat GhcRn) -> Bool)
-> NonEmpty (GenLocated SrcSpanAnnA (Pat GhcRn)) -> Bool
forall (t :: * -> *) a. Foldable t => (a -> Bool) -> t a -> Bool
any LPat GhcRn -> Bool
GenLocated SrcSpanAnnA (Pat GhcRn) -> Bool
lpatternContainsSplice NonEmpty (LPat GhcRn)
NonEmpty (GenLocated SrcSpanAnnA (Pat GhcRn))
lps
          SigPat XSigPat GhcRn
_ LPat GhcRn
lp HsPatSigType (NoGhcTc GhcRn)
_  -> LPat GhcRn -> Bool
lpatternContainsSplice LPat GhcRn
lp
          ListPat XListPat GhcRn
_ [LPat GhcRn]
lps  -> (GenLocated SrcSpanAnnA (Pat GhcRn) -> Bool)
-> [GenLocated SrcSpanAnnA (Pat GhcRn)] -> Bool
forall (t :: * -> *) a. Foldable t => (a -> Bool) -> t a -> Bool
any LPat GhcRn -> Bool
GenLocated SrcSpanAnnA (Pat GhcRn) -> Bool
lpatternContainsSplice [LPat GhcRn]
[GenLocated SrcSpanAnnA (Pat GhcRn)]
lps
          TuplePat XTuplePat GhcRn
_ [LPat GhcRn]
lps Boxity
_ -> (GenLocated SrcSpanAnnA (Pat GhcRn) -> Bool)
-> [GenLocated SrcSpanAnnA (Pat GhcRn)] -> Bool
forall (t :: * -> *) a. Foldable t => (a -> Bool) -> t a -> Bool
any LPat GhcRn -> Bool
GenLocated SrcSpanAnnA (Pat GhcRn) -> Bool
lpatternContainsSplice [LPat GhcRn]
[GenLocated SrcSpanAnnA (Pat GhcRn)]
lps
          SumPat XSumPat GhcRn
_ LPat GhcRn
lp ConTag
_ ConTag
_ -> LPat GhcRn -> Bool
lpatternContainsSplice LPat GhcRn
lp
          ConPat XConPat GhcRn
_ XRec GhcRn (ConLikeP GhcRn)
_ HsConPatDetails GhcRn
cpd  -> (GenLocated SrcSpanAnnA (Pat GhcRn) -> Bool)
-> [GenLocated SrcSpanAnnA (Pat GhcRn)] -> Bool
forall (t :: * -> *) a. Foldable t => (a -> Bool) -> t a -> Bool
any LPat GhcRn -> Bool
GenLocated SrcSpanAnnA (Pat GhcRn) -> Bool
lpatternContainsSplice (HsConPatDetails GhcRn -> [LPat GhcRn]
forall p. UnXRec p => HsConPatDetails p -> [LPat p]
hsConPatArgs HsConPatDetails GhcRn
cpd)
          XPat (HsPatExpanded Pat GhcRn
_orig Pat GhcRn
new) -> Pat GhcRn -> Bool
patternContainsSplice Pat GhcRn
new

          -- The behavior of this case is unimportant, as GHC will throw an error shortly
          -- after reaching this case for other reasons (see TcRnIllegalTypePattern).
          EmbTyPat{} -> Bool
True

          InvisPat{} -> Bool
True

{- Note [Pattern bindings that bind no variables]
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Generally, we want to warn about pattern bindings like
  Just _ = e
because they don't do anything!  But we have three exceptions:

(1) A wildcard pattern
       _ = rhs
  which (a) is not that different from  _v = rhs
        (b) is sometimes used to give a type sig for,
            or an occurrence of, a variable on the RHS

(2) A strict pattern binding; that is, one with an outermost bang
     !Just _ = e
  This can fail, so unlike the lazy variant, it is not a no-op.
  Moreover, #13646 argues that even for single constructor
  types, you might want to write the constructor.  See also #9127.

(3) A splice pattern
      $(th-lhs) = rhs
   It is impossible to determine whether or not th-lhs really
   binds any variable. You have to recurse all the way into the pattern to check
   it doesn't contain any splices like this. See #22057.

Note [Free-variable space leak]
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
We have
    fvs' = trim fvs
and we seq fvs' before turning it as part of a record.

The reason is that trim is sometimes something like
    \xs -> intersectNameSet (mkNameSet bound_names) xs
and we don't want to retain the list bound_names. This showed up in
ticket #1136.
-}

{- *********************************************************************
*                                                                      *
          Dependency analysis and other support functions
*                                                                      *
********************************************************************* -}

depAnalBinds :: [(LHsBind GhcRn, [Name], Uses)]
             -> ([(RecFlag, LHsBinds GhcRn)], DefUses)
-- Dependency analysis; this is important so that
-- unused-binding reporting is accurate
depAnalBinds :: [(LHsBind GhcRn, [Name], NameSet)]
-> ([(RecFlag, LHsBinds GhcRn)], DefUses)
depAnalBinds [(LHsBind GhcRn, [Name], NameSet)]
binds_w_dus
  = ((SCC
   (GenLocated SrcSpanAnnA (HsBindLR GhcRn GhcRn), [Name], NameSet)
 -> (RecFlag, [GenLocated SrcSpanAnnA (HsBindLR GhcRn GhcRn)]))
-> [SCC
      (GenLocated SrcSpanAnnA (HsBindLR GhcRn GhcRn), [Name], NameSet)]
-> [(RecFlag, [GenLocated SrcSpanAnnA (HsBindLR GhcRn GhcRn)])]
forall a b. (a -> b) -> [a] -> [b]
map SCC
  (GenLocated SrcSpanAnnA (HsBindLR GhcRn GhcRn), [Name], NameSet)
-> (RecFlag, [GenLocated SrcSpanAnnA (HsBindLR GhcRn GhcRn)])
forall {a} {b} {c}. SCC (a, b, c) -> (RecFlag, [a])
get_binds [SCC
   (GenLocated SrcSpanAnnA (HsBindLR GhcRn GhcRn), [Name], NameSet)]
sccs, [DefUse] -> DefUses
forall a. [a] -> OrdList a
toOL ([DefUse] -> DefUses) -> [DefUse] -> DefUses
forall a b. (a -> b) -> a -> b
$ (SCC
   (GenLocated SrcSpanAnnA (HsBindLR GhcRn GhcRn), [Name], NameSet)
 -> DefUse)
-> [SCC
      (GenLocated SrcSpanAnnA (HsBindLR GhcRn GhcRn), [Name], NameSet)]
-> [DefUse]
forall a b. (a -> b) -> [a] -> [b]
map SCC
  (GenLocated SrcSpanAnnA (HsBindLR GhcRn GhcRn), [Name], NameSet)
-> DefUse
forall {a}. SCC (a, [Name], NameSet) -> DefUse
get_du [SCC
   (GenLocated SrcSpanAnnA (HsBindLR GhcRn GhcRn), [Name], NameSet)]
sccs)
  where
    sccs :: [SCC
   (GenLocated SrcSpanAnnA (HsBindLR GhcRn GhcRn), [Name], NameSet)]
sccs = ((GenLocated SrcSpanAnnA (HsBindLR GhcRn GhcRn), [Name], NameSet)
 -> [Name])
-> ((GenLocated SrcSpanAnnA (HsBindLR GhcRn GhcRn), [Name],
     NameSet)
    -> [Name])
-> [(GenLocated SrcSpanAnnA (HsBindLR GhcRn GhcRn), [Name],
     NameSet)]
-> [SCC
      (GenLocated SrcSpanAnnA (HsBindLR GhcRn GhcRn), [Name], NameSet)]
forall node.
(node -> [Name]) -> (node -> [Name]) -> [node] -> [SCC node]
depAnal (\(GenLocated SrcSpanAnnA (HsBindLR GhcRn GhcRn)
_, [Name]
defs, NameSet
_) -> [Name]
defs)
                   (\(GenLocated SrcSpanAnnA (HsBindLR GhcRn GhcRn)
_, [Name]
_, NameSet
uses) -> NameSet -> [Name]
forall elt. UniqSet elt -> [elt]
nonDetEltsUniqSet NameSet
uses)
                   -- It's OK to use nonDetEltsUniqSet here as explained in
                   -- Note [depAnal determinism] in GHC.Types.Name.Env.
                   [(LHsBind GhcRn, [Name], NameSet)]
[(GenLocated SrcSpanAnnA (HsBindLR GhcRn GhcRn), [Name], NameSet)]
binds_w_dus

    get_binds :: SCC (a, b, c) -> (RecFlag, [a])
get_binds (AcyclicSCC (a
bind, b
_, c
_)) = (RecFlag
NonRecursive, [a
bind])
    get_binds (CyclicSCC  [(a, b, c)]
binds_w_dus)  = (RecFlag
Recursive, [a
b | (a
b,b
_,c
_) <- [(a, b, c)]
binds_w_dus])

    get_du :: SCC (a, [Name], NameSet) -> DefUse
get_du (AcyclicSCC (a
_, [Name]
bndrs, NameSet
uses)) = (NameSet -> Maybe NameSet
forall a. a -> Maybe a
Just ([Name] -> NameSet
mkNameSet [Name]
bndrs), NameSet
uses)
    get_du (CyclicSCC  [(a, [Name], NameSet)]
binds_w_dus)      = (NameSet -> Maybe NameSet
forall a. a -> Maybe a
Just NameSet
defs, NameSet
uses)
        where
          defs :: NameSet
defs = [Name] -> NameSet
mkNameSet [Name
b | (a
_,[Name]
bs,NameSet
_) <- [(a, [Name], NameSet)]
binds_w_dus, Name
b <- [Name]
bs]
          uses :: NameSet
uses = [NameSet] -> NameSet
unionNameSets [NameSet
u | (a
_,[Name]
_,NameSet
u) <- [(a, [Name], NameSet)]
binds_w_dus]

---------------------
-- Bind the top-level forall'd type variables in the sigs.
-- E.g  f :: forall a. a -> a
--      f = rhs
--      The 'a' scopes over the rhs
--
-- NB: there'll usually be just one (for a function binding)
--     but if there are many, one may shadow the rest; too bad!
--      e.g  x :: forall a. [a] -> [a]
--           y :: forall a. [(a,a)] -> a
--           (x,y) = e
--      In e, 'a' will be in scope, and it'll be the one from 'y'!

mkScopedTvFn :: [LSig GhcRn] -> (Name -> [Name])
-- Return a lookup function that maps an Id Name to the names
-- of the type variables that should scope over its body.
mkScopedTvFn :: [LSig GhcRn] -> Name -> [Name]
mkScopedTvFn [LSig GhcRn]
sigs = \Name
n -> NameEnv [Name] -> Name -> Maybe [Name]
forall a. NameEnv a -> Name -> Maybe a
lookupNameEnv NameEnv [Name]
env Name
n Maybe [Name] -> [Name] -> [Name]
forall a. Maybe a -> a -> a
`orElse` []
  where
    env :: NameEnv [Name]
env = (LSig GhcRn -> Maybe ([GenLocated SrcSpanAnnN Name], [Name]))
-> [LSig GhcRn] -> NameEnv [Name]
forall a.
(LSig GhcRn -> Maybe ([GenLocated SrcSpanAnnN Name], a))
-> [LSig GhcRn] -> NameEnv a
mkHsSigEnv LSig GhcRn -> Maybe ([GenLocated SrcSpanAnnN Name], [Name])
get_scoped_tvs [LSig GhcRn]
sigs

    get_scoped_tvs :: LSig GhcRn -> Maybe ([LocatedN Name], [Name])
    -- Returns (binders, scoped tvs for those binders)
    get_scoped_tvs :: LSig GhcRn -> Maybe ([GenLocated SrcSpanAnnN Name], [Name])
get_scoped_tvs (L SrcSpanAnnA
_ (ClassOpSig XClassOpSig GhcRn
_ Bool
_ [XRec GhcRn (IdP GhcRn)]
names LHsSigType GhcRn
sig_ty))
      = ([GenLocated SrcSpanAnnN Name], [Name])
-> Maybe ([GenLocated SrcSpanAnnN Name], [Name])
forall a. a -> Maybe a
Just ([XRec GhcRn (IdP GhcRn)]
[GenLocated SrcSpanAnnN Name]
names, LHsSigType GhcRn -> [Name]
hsScopedTvs LHsSigType GhcRn
sig_ty)
    get_scoped_tvs (L SrcSpanAnnA
_ (TypeSig XTypeSig GhcRn
_ [XRec GhcRn (IdP GhcRn)]
names LHsSigWcType GhcRn
sig_ty))
      = ([GenLocated SrcSpanAnnN Name], [Name])
-> Maybe ([GenLocated SrcSpanAnnN Name], [Name])
forall a. a -> Maybe a
Just ([XRec GhcRn (IdP GhcRn)]
[GenLocated SrcSpanAnnN Name]
names, LHsSigWcType GhcRn -> [Name]
hsWcScopedTvs LHsSigWcType GhcRn
sig_ty)
    get_scoped_tvs (L SrcSpanAnnA
_ (PatSynSig XPatSynSig GhcRn
_ [XRec GhcRn (IdP GhcRn)]
names LHsSigType GhcRn
sig_ty))
      = ([GenLocated SrcSpanAnnN Name], [Name])
-> Maybe ([GenLocated SrcSpanAnnN Name], [Name])
forall a. a -> Maybe a
Just ([XRec GhcRn (IdP GhcRn)]
[GenLocated SrcSpanAnnN Name]
names, LHsSigType GhcRn -> [Name]
hsScopedTvs LHsSigType GhcRn
sig_ty)
    get_scoped_tvs LSig GhcRn
_ = Maybe ([GenLocated SrcSpanAnnN Name], [Name])
forall a. Maybe a
Nothing

-- Process the fixity declarations, making a FastString -> (Located Fixity) map
-- (We keep the location around for reporting duplicate fixity declarations.)
--
-- Checks for duplicates, but not that only locally defined things are fixed.
-- Note: for local fixity declarations, duplicates would also be checked in
--       check_sigs below.  But we also use this function at the top level.

makeMiniFixityEnv :: [LFixitySig GhcPs] -> RnM MiniFixityEnv

makeMiniFixityEnv :: [LFixitySig GhcPs] -> RnM MiniFixityEnv
makeMiniFixityEnv [LFixitySig GhcPs]
decls = (MiniFixityEnv
 -> GenLocated SrcSpanAnnA (FixitySig GhcPs) -> RnM MiniFixityEnv)
-> MiniFixityEnv
-> [GenLocated SrcSpanAnnA (FixitySig GhcPs)]
-> RnM MiniFixityEnv
forall (t :: * -> *) (m :: * -> *) b a.
(Foldable t, Monad m) =>
(b -> a -> m b) -> b -> t a -> m b
foldlM MiniFixityEnv -> LFixitySig GhcPs -> RnM MiniFixityEnv
MiniFixityEnv
-> GenLocated SrcSpanAnnA (FixitySig GhcPs) -> RnM MiniFixityEnv
add_one_sig MiniFixityEnv
emptyMiniFixityEnv [LFixitySig GhcPs]
[GenLocated SrcSpanAnnA (FixitySig GhcPs)]
decls
 where
   add_one_sig :: MiniFixityEnv -> LFixitySig GhcPs -> RnM MiniFixityEnv
   add_one_sig :: MiniFixityEnv -> LFixitySig GhcPs -> RnM MiniFixityEnv
add_one_sig MiniFixityEnv
env (L SrcSpanAnnA
loc (FixitySig XFixitySig GhcPs
ns_spec [LIdP GhcPs]
names Fixity
fixity)) =
     (MiniFixityEnv
 -> (SrcSpan, SrcSpan, RdrName, Fixity, NamespaceSpecifier)
 -> RnM MiniFixityEnv)
-> MiniFixityEnv
-> [(SrcSpan, SrcSpan, RdrName, Fixity, NamespaceSpecifier)]
-> RnM MiniFixityEnv
forall (t :: * -> *) (m :: * -> *) b a.
(Foldable t, Monad m) =>
(b -> a -> m b) -> b -> t a -> m b
foldlM MiniFixityEnv
-> (SrcSpan, SrcSpan, RdrName, Fixity, NamespaceSpecifier)
-> RnM MiniFixityEnv
add_one MiniFixityEnv
env [ (SrcSpanAnnA -> SrcSpan
forall a. HasLoc a => a -> SrcSpan
locA SrcSpanAnnA
loc,SrcSpanAnnN -> SrcSpan
forall a. HasLoc a => a -> SrcSpan
locA SrcSpanAnnN
name_loc,RdrName
name,Fixity
fixity, XFixitySig GhcPs
NamespaceSpecifier
ns_spec)
                        | L SrcSpanAnnN
name_loc RdrName
name <- [LIdP GhcPs]
[LocatedN RdrName]
names ]

   add_one :: MiniFixityEnv
-> (SrcSpan, SrcSpan, RdrName, Fixity, NamespaceSpecifier)
-> RnM MiniFixityEnv
add_one MiniFixityEnv
env (SrcSpan
loc, SrcSpan
name_loc, RdrName
name, Fixity
fixity, NamespaceSpecifier
ns_spec) = do
     { -- this fixity decl is a duplicate iff
       -- the ReaderName's OccName's FastString is already in the env
       -- (we only need to check the local fix_env because
       --  definitions of non-local will be caught elsewhere)
       let { fs :: FastString
fs = OccName -> FastString
occNameFS (RdrName -> OccName
rdrNameOcc RdrName
name)
           ; fix_item :: GenLocated SrcSpan Fixity
fix_item = SrcSpan -> Fixity -> GenLocated SrcSpan Fixity
forall l e. l -> e -> GenLocated l e
L SrcSpan
loc Fixity
fixity};

       case NamespaceSpecifier
-> MiniFixityEnv -> FastString -> Maybe (GenLocated SrcSpan Fixity)
search_for_dups NamespaceSpecifier
ns_spec MiniFixityEnv
env FastString
fs of
         Maybe (GenLocated SrcSpan Fixity)
Nothing -> MiniFixityEnv -> RnM MiniFixityEnv
forall a. a -> IOEnv (Env TcGblEnv TcLclEnv) a
forall (m :: * -> *) a. Monad m => a -> m a
return (MiniFixityEnv -> RnM MiniFixityEnv)
-> MiniFixityEnv -> RnM MiniFixityEnv
forall a b. (a -> b) -> a -> b
$ NamespaceSpecifier
-> MiniFixityEnv
-> FastString
-> GenLocated SrcSpan Fixity
-> MiniFixityEnv
extend_mini_fixity_env NamespaceSpecifier
ns_spec MiniFixityEnv
env FastString
fs GenLocated SrcSpan Fixity
fix_item
         Just (L SrcSpan
loc' Fixity
_) -> do
           { SrcSpan -> TcM () -> TcM ()
forall a. SrcSpan -> TcRn a -> TcRn a
setSrcSpan SrcSpan
loc (TcM () -> TcM ()) -> TcM () -> TcM ()
forall a b. (a -> b) -> a -> b
$
             SrcSpan -> TcRnMessage -> TcM ()
addErrAt SrcSpan
name_loc (SrcSpan -> RdrName -> TcRnMessage
TcRnMultipleFixityDecls SrcSpan
loc' RdrName
name)
           ; MiniFixityEnv -> RnM MiniFixityEnv
forall a. a -> IOEnv (Env TcGblEnv TcLclEnv) a
forall (m :: * -> *) a. Monad m => a -> m a
return MiniFixityEnv
env}
     }
   search_for_dups :: NamespaceSpecifier
-> MiniFixityEnv -> FastString -> Maybe (GenLocated SrcSpan Fixity)
search_for_dups NamespaceSpecifier
ns_spec MFE{FastStringEnv (GenLocated SrcSpan Fixity)
mfe_data_level_names :: FastStringEnv (GenLocated SrcSpan Fixity)
mfe_data_level_names :: MiniFixityEnv -> FastStringEnv (GenLocated SrcSpan Fixity)
mfe_data_level_names, FastStringEnv (GenLocated SrcSpan Fixity)
mfe_type_level_names :: FastStringEnv (GenLocated SrcSpan Fixity)
mfe_type_level_names :: MiniFixityEnv -> FastStringEnv (GenLocated SrcSpan Fixity)
mfe_type_level_names} FastString
fs
    = case NamespaceSpecifier
ns_spec of
      NamespaceSpecifier
NoNamespaceSpecifier -> case FastStringEnv (GenLocated SrcSpan Fixity)
-> FastString -> Maybe (GenLocated SrcSpan Fixity)
forall a. FastStringEnv a -> FastString -> Maybe a
lookupFsEnv FastStringEnv (GenLocated SrcSpan Fixity)
mfe_data_level_names FastString
fs of
        -- We only need to find a single duplicate to emit an error about
        -- multiple fixity decls. Therefore, if we find a duplicate in the
        -- term-level namespace, then there is no need to look in the type-level namespace.
        Maybe (GenLocated SrcSpan Fixity)
Nothing -> FastStringEnv (GenLocated SrcSpan Fixity)
-> FastString -> Maybe (GenLocated SrcSpan Fixity)
forall a. FastStringEnv a -> FastString -> Maybe a
lookupFsEnv FastStringEnv (GenLocated SrcSpan Fixity)
mfe_type_level_names FastString
fs
        Maybe (GenLocated SrcSpan Fixity)
just_dup -> Maybe (GenLocated SrcSpan Fixity)
just_dup
      TypeNamespaceSpecifier{} -> FastStringEnv (GenLocated SrcSpan Fixity)
-> FastString -> Maybe (GenLocated SrcSpan Fixity)
forall a. FastStringEnv a -> FastString -> Maybe a
lookupFsEnv FastStringEnv (GenLocated SrcSpan Fixity)
mfe_type_level_names FastString
fs
      DataNamespaceSpecifier{} -> FastStringEnv (GenLocated SrcSpan Fixity)
-> FastString -> Maybe (GenLocated SrcSpan Fixity)
forall a. FastStringEnv a -> FastString -> Maybe a
lookupFsEnv FastStringEnv (GenLocated SrcSpan Fixity)
mfe_data_level_names FastString
fs

   extend_mini_fixity_env :: NamespaceSpecifier
-> MiniFixityEnv
-> FastString
-> GenLocated SrcSpan Fixity
-> MiniFixityEnv
extend_mini_fixity_env NamespaceSpecifier
ns_spec env :: MiniFixityEnv
env@MFE{FastStringEnv (GenLocated SrcSpan Fixity)
mfe_data_level_names :: MiniFixityEnv -> FastStringEnv (GenLocated SrcSpan Fixity)
mfe_data_level_names :: FastStringEnv (GenLocated SrcSpan Fixity)
mfe_data_level_names, FastStringEnv (GenLocated SrcSpan Fixity)
mfe_type_level_names :: MiniFixityEnv -> FastStringEnv (GenLocated SrcSpan Fixity)
mfe_type_level_names :: FastStringEnv (GenLocated SrcSpan Fixity)
mfe_type_level_names} FastString
fs GenLocated SrcSpan Fixity
fix_item
    = case NamespaceSpecifier
ns_spec of
      NamespaceSpecifier
NoNamespaceSpecifier     -> MFE { mfe_data_level_names :: FastStringEnv (GenLocated SrcSpan Fixity)
mfe_data_level_names = (FastStringEnv (GenLocated SrcSpan Fixity)
-> FastString
-> GenLocated SrcSpan Fixity
-> FastStringEnv (GenLocated SrcSpan Fixity)
forall a. FastStringEnv a -> FastString -> a -> FastStringEnv a
extendFsEnv FastStringEnv (GenLocated SrcSpan Fixity)
mfe_data_level_names FastString
fs GenLocated SrcSpan Fixity
fix_item)
                                      , mfe_type_level_names :: FastStringEnv (GenLocated SrcSpan Fixity)
mfe_type_level_names = (FastStringEnv (GenLocated SrcSpan Fixity)
-> FastString
-> GenLocated SrcSpan Fixity
-> FastStringEnv (GenLocated SrcSpan Fixity)
forall a. FastStringEnv a -> FastString -> a -> FastStringEnv a
extendFsEnv FastStringEnv (GenLocated SrcSpan Fixity)
mfe_type_level_names FastString
fs GenLocated SrcSpan Fixity
fix_item)}

      TypeNamespaceSpecifier{} -> MiniFixityEnv
env { mfe_type_level_names = (extendFsEnv mfe_type_level_names fs fix_item)}

      DataNamespaceSpecifier{} -> MiniFixityEnv
env { mfe_data_level_names = (extendFsEnv mfe_data_level_names fs fix_item)}


-- | Multiplicity annotations are a simple wrapper around types. As such,
-- renaming them is a straightforward wrapper around 'rnLHsType'.
rnHsMultAnn :: HsMultAnn GhcPs -> RnM (HsMultAnn GhcRn, FreeVars)
rnHsMultAnn :: HsMultAnn GhcPs -> RnM (HsMultAnn GhcRn, NameSet)
rnHsMultAnn (HsNoMultAnn XNoMultAnn GhcPs
_) = (HsMultAnn GhcRn, NameSet) -> RnM (HsMultAnn GhcRn, NameSet)
forall a. a -> IOEnv (Env TcGblEnv TcLclEnv) a
forall (m :: * -> *) a. Monad m => a -> m a
return (XNoMultAnn GhcRn -> HsMultAnn GhcRn
forall pass. XNoMultAnn pass -> HsMultAnn pass
HsNoMultAnn NoExtField
XNoMultAnn GhcRn
noExtField, NameSet
emptyFVs)
rnHsMultAnn (HsPct1Ann XPct1Ann GhcPs
_) = (HsMultAnn GhcRn, NameSet) -> RnM (HsMultAnn GhcRn, NameSet)
forall a. a -> IOEnv (Env TcGblEnv TcLclEnv) a
forall (m :: * -> *) a. Monad m => a -> m a
return (XPct1Ann GhcRn -> HsMultAnn GhcRn
forall pass. XPct1Ann pass -> HsMultAnn pass
HsPct1Ann NoExtField
XPct1Ann GhcRn
noExtField, NameSet
emptyFVs)
rnHsMultAnn (HsMultAnn XMultAnn GhcPs
_ LHsType (NoGhcTc GhcPs)
p) = do
  (p', freeVars') <- HsDocContext -> LHsType GhcPs -> RnM (LHsType GhcRn, NameSet)
rnLHsType HsDocContext
PatCtx LHsType (NoGhcTc GhcPs)
LHsType GhcPs
p
  return $ (HsMultAnn noExtField p', freeVars')

{- *********************************************************************
*                                                                      *
                Pattern synonym bindings
*                                                                      *
********************************************************************* -}

rnPatSynBind :: (Name -> [Name])           -- Signature tyvar function
             -> PatSynBind GhcRn GhcPs
             -> RnM (PatSynBind GhcRn GhcRn, [Name], Uses)
rnPatSynBind :: (Name -> [Name])
-> PatSynBind GhcRn GhcPs
-> RnM (PatSynBind GhcRn GhcRn, [Name], NameSet)
rnPatSynBind Name -> [Name]
sig_fn bind :: PatSynBind GhcRn GhcPs
bind@(PSB { psb_id :: forall idL idR. PatSynBind idL idR -> LIdP idL
psb_id = L SrcSpanAnnN
l Name
name
                              , psb_args :: forall idL idR. PatSynBind idL idR -> HsPatSynDetails idR
psb_args = HsPatSynDetails GhcPs
details
                              , psb_def :: forall idL idR. PatSynBind idL idR -> LPat idR
psb_def = LPat GhcPs
pat
                              , psb_dir :: forall idL idR. PatSynBind idL idR -> HsPatSynDir idR
psb_dir = HsPatSynDir GhcPs
dir })
       -- invariant: no free vars here when it's a FunBind
  = do  { pattern_synonym_ok <- Extension -> TcRnIf TcGblEnv TcLclEnv Bool
forall gbl lcl. Extension -> TcRnIf gbl lcl Bool
xoptM Extension
LangExt.PatternSynonyms
        ; unless pattern_synonym_ok (addErr TcRnIllegalPatternSynonymDecl)
        ; let scoped_tvs = Name -> [Name]
sig_fn Name
name

        ; ((pat', details'), fvs1) <- bindSigTyVarsFV scoped_tvs $
                                      rnPat PatSyn pat $ \LPat GhcRn
pat' ->
         -- We check the 'RdrName's instead of the 'Name's
         -- so that the binding locations are reported
         -- from the left-hand side
            case HsPatSynDetails GhcPs
details of
               PrefixCon [Void]
_ [LIdP GhcPs]
vars ->
                   do { [LocatedN RdrName] -> TcM ()
checkDupRdrNames [LIdP GhcPs]
[LocatedN RdrName]
vars
                      ; names <- (LocatedN RdrName -> RnM (GenLocated SrcSpanAnnN Name))
-> [LocatedN RdrName]
-> IOEnv (Env TcGblEnv TcLclEnv) [GenLocated SrcSpanAnnN Name]
forall (t :: * -> *) (m :: * -> *) a b.
(Traversable t, Monad m) =>
(a -> m b) -> t a -> m (t b)
forall (m :: * -> *) a b. Monad m => (a -> m b) -> [a] -> m [b]
mapM LocatedN RdrName -> RnM (GenLocated SrcSpanAnnN Name)
forall {ann}.
GenLocated (EpAnn ann) RdrName
-> TcRn (GenLocated (EpAnn ann) Name)
lookupPatSynBndr [LIdP GhcPs]
[LocatedN RdrName]
vars
                      ; return ( (pat', PrefixCon noTypeArgs names)
                               , mkFVs (map unLoc names)) }
               InfixCon LIdP GhcPs
var1 LIdP GhcPs
var2 ->
                   do { [LocatedN RdrName] -> TcM ()
checkDupRdrNames [LIdP GhcPs
LocatedN RdrName
var1, LIdP GhcPs
LocatedN RdrName
var2]
                      ; name1 <- LocatedN RdrName -> RnM (GenLocated SrcSpanAnnN Name)
forall {ann}.
GenLocated (EpAnn ann) RdrName
-> TcRn (GenLocated (EpAnn ann) Name)
lookupPatSynBndr LIdP GhcPs
LocatedN RdrName
var1
                      ; name2 <- lookupPatSynBndr var2
                      -- ; checkPrecMatch -- TODO
                      ; return ( (pat', InfixCon name1 name2)
                               , mkFVs (map unLoc [name1, name2])) }
               RecCon [RecordPatSynField GhcPs]
vars ->
                   do { [LocatedN RdrName] -> TcM ()
checkDupRdrNames ((RecordPatSynField GhcPs -> LocatedN RdrName)
-> [RecordPatSynField GhcPs] -> [LocatedN RdrName]
forall a b. (a -> b) -> [a] -> [b]
map (FieldOcc GhcPs -> XRec GhcPs RdrName
FieldOcc GhcPs -> LocatedN RdrName
forall pass. FieldOcc pass -> XRec pass RdrName
foLabel (FieldOcc GhcPs -> LocatedN RdrName)
-> (RecordPatSynField GhcPs -> FieldOcc GhcPs)
-> RecordPatSynField GhcPs
-> LocatedN RdrName
forall b c a. (b -> c) -> (a -> b) -> a -> c
. RecordPatSynField GhcPs -> FieldOcc GhcPs
forall pass. RecordPatSynField pass -> FieldOcc pass
recordPatSynField) [RecordPatSynField GhcPs]
vars)
                      ; fls <- HasDebugCallStack => Name -> RnM [FieldLabel]
Name -> RnM [FieldLabel]
lookupConstructorFields Name
name
                      ; let fld_env = [(FastString, FieldLabel)] -> FastStringEnv FieldLabel
forall a. [(FastString, a)] -> FastStringEnv a
mkFsEnv [ (FieldLabelString -> FastString
field_label (FieldLabelString -> FastString) -> FieldLabelString -> FastString
forall a b. (a -> b) -> a -> b
$ FieldLabel -> FieldLabelString
flLabel FieldLabel
fl, FieldLabel
fl) | FieldLabel
fl <- [FieldLabel]
fls ]
                      ; let rnRecordPatSynField
                              (RecordPatSynField { recordPatSynField :: forall pass. RecordPatSynField pass -> FieldOcc pass
recordPatSynField  = FieldOcc GhcPs
visible
                                                 , recordPatSynPatVar :: forall pass. RecordPatSynField pass -> LIdP pass
recordPatSynPatVar = LIdP GhcPs
hidden })
                              = do { let visible' :: FieldOcc GhcRn
visible' = FastStringEnv FieldLabel -> FieldOcc GhcPs -> FieldOcc GhcRn
lookupField FastStringEnv FieldLabel
fld_env FieldOcc GhcPs
visible
                                   ; hidden'  <- LocatedN RdrName -> RnM (GenLocated SrcSpanAnnN Name)
forall {ann}.
GenLocated (EpAnn ann) RdrName
-> TcRn (GenLocated (EpAnn ann) Name)
lookupPatSynBndr LIdP GhcPs
LocatedN RdrName
hidden
                                   ; return $ RecordPatSynField { recordPatSynField  = visible'
                                                                , recordPatSynPatVar = hidden' } }
                      ; names <- mapM rnRecordPatSynField  vars
                      ; return ( (pat', RecCon names)
                               , mkFVs (map (unLoc . recordPatSynPatVar) names)) }

        ; (dir', fvs2) <- case dir of
            HsPatSynDir GhcPs
Unidirectional -> (HsPatSynDir GhcRn, NameSet)
-> IOEnv (Env TcGblEnv TcLclEnv) (HsPatSynDir GhcRn, NameSet)
forall a. a -> IOEnv (Env TcGblEnv TcLclEnv) a
forall (m :: * -> *) a. Monad m => a -> m a
return (HsPatSynDir GhcRn
forall id. HsPatSynDir id
Unidirectional, NameSet
emptyFVs)
            HsPatSynDir GhcPs
ImplicitBidirectional -> (HsPatSynDir GhcRn, NameSet)
-> IOEnv (Env TcGblEnv TcLclEnv) (HsPatSynDir GhcRn, NameSet)
forall a. a -> IOEnv (Env TcGblEnv TcLclEnv) a
forall (m :: * -> *) a. Monad m => a -> m a
return (HsPatSynDir GhcRn
forall id. HsPatSynDir id
ImplicitBidirectional, NameSet
emptyFVs)
            ExplicitBidirectional MatchGroup GhcPs (LHsExpr GhcPs)
mg ->
                do { (mg', fvs) <- [Name]
-> RnM
     (MatchGroup GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn)), NameSet)
-> RnM
     (MatchGroup GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn)), NameSet)
forall a. [Name] -> RnM (a, NameSet) -> RnM (a, NameSet)
bindSigTyVarsFV [Name]
scoped_tvs (RnM
   (MatchGroup GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn)), NameSet)
 -> RnM
      (MatchGroup GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn)),
       NameSet))
-> RnM
     (MatchGroup GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn)), NameSet)
-> RnM
     (MatchGroup GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn)), NameSet)
forall a b. (a -> b) -> a -> b
$
                                   HsMatchContextRn
-> (LocatedA (HsExpr GhcPs)
    -> IOEnv
         (Env TcGblEnv TcLclEnv)
         (GenLocated SrcSpanAnnA (HsExpr GhcRn), NameSet))
-> MatchGroup GhcPs (LocatedA (HsExpr GhcPs))
-> RnM
     (MatchGroup GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn)), NameSet)
forall (body :: * -> *).
(Outputable (body GhcPs), AnnoBody body) =>
HsMatchContextRn
-> (LocatedA (body GhcPs) -> RnM (LocatedA (body GhcRn), NameSet))
-> MatchGroup GhcPs (LocatedA (body GhcPs))
-> RnM (MatchGroup GhcRn (LocatedA (body GhcRn)), NameSet)
rnMatchGroup (GenLocated SrcSpanAnnN Name
-> AnnFunRhs -> HsMatchContext (GenLocated SrcSpanAnnN Name)
forall fn. fn -> AnnFunRhs -> HsMatchContext fn
mkPrefixFunRhs (SrcSpanAnnN -> Name -> GenLocated SrcSpanAnnN Name
forall l e. l -> e -> GenLocated l e
L SrcSpanAnnN
l Name
name) AnnFunRhs
forall a. NoAnn a => a
noAnn)
                                                LHsExpr GhcPs -> RnM (LHsExpr GhcRn, NameSet)
LocatedA (HsExpr GhcPs)
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     (GenLocated SrcSpanAnnA (HsExpr GhcRn), NameSet)
rnLExpr MatchGroup GhcPs (LHsExpr GhcPs)
MatchGroup GhcPs (LocatedA (HsExpr GhcPs))
mg
                   ; return (ExplicitBidirectional mg', fvs) }

        ; mod <- getModule
        ; let fvs = NameSet
fvs1 NameSet -> NameSet -> NameSet
`plusFV` NameSet
fvs2
              fvs' = (Name -> Bool) -> NameSet -> NameSet
filterNameSet (Module -> Name -> Bool
nameIsLocalOrFrom Module
mod) NameSet
fvs
                -- Keep locally-defined Names
                -- As well as dependency analysis, we need these for the
                -- MonoLocalBinds test in GHC.Tc.Gen.Bind.decideGeneralisationPlan

              bind' = PatSynBind GhcRn GhcPs
bind{ psb_args = details'
                          , psb_def = pat'
                          , psb_dir = dir'
                          , psb_ext = fvs' }
              selector_names = case HsConDetails
  Void (GenLocated SrcSpanAnnN Name) [RecordPatSynField GhcRn]
details' of
                                 RecCon [RecordPatSynField GhcRn]
names ->
                                  (RecordPatSynField GhcRn -> Name)
-> [RecordPatSynField GhcRn] -> [Name]
forall a b. (a -> b) -> [a] -> [b]
map (FieldOcc GhcRn -> XCFieldOcc GhcRn
FieldOcc GhcRn -> Name
forall pass. FieldOcc pass -> XCFieldOcc pass
foExt (FieldOcc GhcRn -> Name)
-> (RecordPatSynField GhcRn -> FieldOcc GhcRn)
-> RecordPatSynField GhcRn
-> Name
forall b c a. (b -> c) -> (a -> b) -> a -> c
. RecordPatSynField GhcRn -> FieldOcc GhcRn
forall pass. RecordPatSynField pass -> FieldOcc pass
recordPatSynField) [RecordPatSynField GhcRn]
names
                                 HsConDetails
  Void (GenLocated SrcSpanAnnN Name) [RecordPatSynField GhcRn]
_ -> []

        ; fvs' `seq` -- See Note [Free-variable space leak]
          return (bind', name : selector_names , fvs1)
          -- Why fvs1?  See Note [Pattern synonym builders don't yield dependencies]
      }
  where
    -- See Note [Renaming pattern synonym variables]
    lookupPatSynBndr :: GenLocated (EpAnn ann) RdrName
-> TcRn (GenLocated (EpAnn ann) Name)
lookupPatSynBndr = (RdrName -> TcM Name)
-> GenLocated (EpAnn ann) RdrName
-> TcRn (GenLocated (EpAnn ann) Name)
forall a b ann.
(a -> TcM b)
-> GenLocated (EpAnn ann) a -> TcRn (GenLocated (EpAnn ann) b)
wrapLocMA RdrName -> TcM Name
lookupLocalOccRn


{-
Note [Renaming pattern synonym variables]
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

We rename pattern synonym declarations backwards to normal to reuse
the logic already implemented for renaming patterns.

We first rename the RHS of a declaration which brings into
scope the variables bound by the pattern (as they would be
in normal function definitions). We then lookup the variables
which we want to bind in this local environment.

It is crucial that we then only lookup in the *local* environment which
only contains the variables brought into scope by the pattern and nothing
else. Amazingly no-one encountered this bug for 3 GHC versions but
it was possible to define a pattern synonym which referenced global
identifiers and worked correctly.

```
x = 5

pattern P :: Int -> ()
pattern P x <- _

f (P x) = x

> f () = 5
```

See #13470 for the original report.

Note [Pattern synonym builders don't yield dependencies]
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
When renaming a pattern synonym that has an explicit builder,
references in the builder definition should not be used when
calculating dependencies. For example, consider the following pattern
synonym definition:

pattern P x <- C1 x where
  P x = f (C1 x)

f (P x) = C2 x

In this case, 'P' needs to be typechecked in two passes:

1. Typecheck the pattern definition of 'P', which fully determines the
   type of 'P'. This step doesn't require knowing anything about 'f',
   since the builder definition is not looked at.

2. Typecheck the builder definition, which needs the typechecked
   definition of 'f' to be in scope; done by calls oo tcPatSynBuilderBind
   in GHC.Tc.Gen.Bind.tcValBinds.

This behaviour is implemented in 'tcValBinds', but it crucially
depends on 'P' not being put in a recursive group with 'f' (which
would make it look like a recursive pattern synonym a la 'pattern P =
P' which is unsound and rejected).

So:
 * We do not include builder fvs in the Uses returned by rnPatSynBind
   (which is then used for dependency analysis)
 * But we /do/ include them in the psb_fvs for the PatSynBind
 * In rnValBinds we record these builder uses, to avoid bogus
   unused-variable warnings (#12548)
-}

{- *********************************************************************
*                                                                      *
                Class/instance method bindings
*                                                                      *
********************************************************************* -}

{- @rnMethodBinds@ is used for the method bindings of a class and an instance
declaration.   Like @rnBinds@ but without dependency analysis.

NOTA BENE: we record each {\em binder} of a method-bind group as a free variable.
That's crucial when dealing with an instance decl:
\begin{verbatim}
        instance Foo (T a) where
           op x = ...
\end{verbatim}
This might be the {\em sole} occurrence of @op@ for an imported class @Foo@,
and unless @op@ occurs we won't treat the type signature of @op@ in the class
decl for @Foo@ as a source of instance-decl gates.  But we should!  Indeed,
in many ways the @op@ in an instance decl is just like an occurrence, not
a binder.
-}

rnMethodBinds :: Bool                   -- True <=> is a class declaration
              -> Name                   -- Class name
              -> [Name]                 -- Type variables from the class/instance header
              -> LHsBinds GhcPs         -- Binds
              -> [LSig GhcPs]           -- and signatures/pragmas
              -> RnM (LHsBinds GhcRn, [LSig GhcRn], FreeVars)
-- Used for
--   * the default method bindings in a class decl
--   * the method bindings in an instance decl
rnMethodBinds :: Bool
-> Name
-> [Name]
-> LHsBindsLR GhcPs GhcPs
-> [XRec GhcPs (Sig GhcPs)]
-> RnM (LHsBinds GhcRn, [LSig GhcRn], NameSet)
rnMethodBinds Bool
is_cls_decl Name
cls [Name]
ktv_names LHsBindsLR GhcPs GhcPs
binds [XRec GhcPs (Sig GhcPs)]
sigs
  = do { [LocatedN RdrName] -> TcM ()
checkDupRdrNames (LHsBindsLR GhcPs GhcPs -> [LIdP GhcPs]
forall idL idR. UnXRec idL => LHsBindsLR idL idR -> [LIdP idL]
collectMethodBinders LHsBindsLR GhcPs GhcPs
binds)
             -- Check that the same method is not given twice in the
             -- same instance decl      instance C T where
             --                       f x = ...
             --                       g y = ...
             --                       f x = ...
             -- We must use checkDupRdrNames because the Name of the
             -- method is the Name of the class selector, whose SrcSpan
             -- points to the class declaration; and we use rnMethodBinds
             -- for instance decls too

       -- Rename the bindings LHSs
       ; binds' <- (GenLocated SrcSpanAnnA (HsBind GhcPs)
 -> [LocatedA (HsBindLR GhcRn GhcPs)]
 -> IOEnv (Env TcGblEnv TcLclEnv) [LocatedA (HsBindLR GhcRn GhcPs)])
-> [LocatedA (HsBindLR GhcRn GhcPs)]
-> [GenLocated SrcSpanAnnA (HsBind GhcPs)]
-> IOEnv (Env TcGblEnv TcLclEnv) [LocatedA (HsBindLR GhcRn GhcPs)]
forall (t :: * -> *) (m :: * -> *) a b.
(Foldable t, Monad m) =>
(a -> b -> m b) -> b -> t a -> m b
foldrM (Bool
-> Name
-> LHsBindLR GhcPs GhcPs
-> LHsBindsLR GhcRn GhcPs
-> RnM (LHsBindsLR GhcRn GhcPs)
rnMethodBindLHS Bool
is_cls_decl Name
cls) [] LHsBindsLR GhcPs GhcPs
[GenLocated SrcSpanAnnA (HsBind GhcPs)]
binds

       -- Rename the pragmas and signatures
       -- Annoyingly the type variables /are/ in scope for signatures, but
       -- /are not/ in scope in SPECIALISE and SPECIALISE instance pragmas.
       -- See Note [Type variable scoping in SPECIALISE pragmas].
       ; let (spec_prags, other_sigs) = partition (isSpecLSig <||> isSpecInstLSig) sigs
             bound_nms = [Name] -> NameSet
mkNameSet (CollectFlag GhcRn -> LHsBindsLR GhcRn GhcPs -> [IdP GhcRn]
forall p idR.
CollectPass p =>
CollectFlag p -> LHsBindsLR p idR -> [IdP p]
collectHsBindsBinders CollectFlag GhcRn
forall p. CollectFlag p
CollNoDictBinders LHsBindsLR GhcRn GhcPs
[LocatedA (HsBindLR GhcRn GhcPs)]
binds')
             sig_ctxt | Bool
is_cls_decl = Name -> HsSigCtxt
ClsDeclCtxt Name
cls
                      | Bool
otherwise   = NameSet -> HsSigCtxt
InstDeclCtxt NameSet
bound_nms
       ; (spec_prags', spg_fvs) <- renameSigs sig_ctxt spec_prags
       ; (other_sigs', sig_fvs) <- bindLocalNamesFV ktv_names $
                                      renameSigs sig_ctxt other_sigs
       ; let localCompletePrags = [LSig GhcRn] -> CompleteMatches
localCompletePragmas [LSig GhcRn]
[GenLocated SrcSpanAnnA (Sig GhcRn)]
spec_prags'

       -- Update the TcGblEnv with renamed COMPLETE pragmas from the current
       -- module, for pattern irrefutability checking in do notation.
       ; updGblEnv (\TcGblEnv
gblEnv -> TcGblEnv
gblEnv { tcg_complete_matches = tcg_complete_matches gblEnv ++ localCompletePrags}) $
    do {
       -- Rename the bindings RHSs.  Again there's an issue about whether the
       -- type variables from the class/instance head are in scope.
       -- Answer no in Haskell 2010, but yes if you have -XScopedTypeVariables
       ; (binds'', bind_fvs) <- bindSigTyVarsFV ktv_names $
              do { binds_w_dus <- mapM (rnLBind (mkScopedTvFn other_sigs')) binds'
                 ; let bind_fvs = ((GenLocated SrcSpanAnnA (HsBindLR GhcRn GhcRn), [Name], NameSet)
 -> NameSet -> NameSet)
-> NameSet
-> [(GenLocated SrcSpanAnnA (HsBindLR GhcRn GhcRn), [Name],
     NameSet)]
-> NameSet
forall a b. (a -> b -> b) -> b -> [a] -> b
forall (t :: * -> *) a b.
Foldable t =>
(a -> b -> b) -> b -> t a -> b
foldr (\(GenLocated SrcSpanAnnA (HsBindLR GhcRn GhcRn)
_,[Name]
_,NameSet
fv1) NameSet
fv2 -> NameSet
fv1 NameSet -> NameSet -> NameSet
`plusFV` NameSet
fv2)
                                           NameSet
emptyFVs [(GenLocated SrcSpanAnnA (HsBindLR GhcRn GhcRn), [Name], NameSet)]
binds_w_dus
                 ; return (map fstOf3 binds_w_dus, bind_fvs) }

       ; return ( binds'', spec_prags' ++ other_sigs'
                , sig_fvs `plusFV` spg_fvs `plusFV` bind_fvs) } }

{- Note [Type variable scoping in SPECIALISE pragmas]
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
When renaming the methods of a class or instance declaration, we must be careful
with the scoping of the type variables that occur in SPECIALISE and SPECIALISE instance
pragmas: the type variables from the class/instance header DO NOT scope over these,
unlike class/instance method type signatures.

Examples:

  1. SPECIALISE

    class C a where
      meth :: a
    instance C (Maybe a) where
      meth = Nothing
      {-# SPECIALISE INLINE meth :: Maybe [a] #-}

  2. SPECIALISE instance

    instance Eq a => Eq (T a) where
       (==) :: a -> a -> a
       {-# SPECIALISE instance Eq a => Eq (T [a]) #-}

  In both cases, the type variable `a` mentioned in the PRAGMA is NOT the same
  as the type variable `a` from the instance header.
  For example, the SPECIALISE instance pragma above is a shorthand for

      {-# SPECIALISE instance forall a. Eq a => Eq (T [a]) #-}

  which is alpha-equivalent to

      {-# SPECIALISE instance forall b. Eq b => Eq (T [b]) #-}

  This shows that the type variables are not bound in the header.

  Getting this scoping wrong can lead to out-of-scope type variable errors from
  Core Lint, see e.g. #22913.
-}

rnMethodBindLHS :: Bool -> Name
                -> LHsBindLR GhcPs GhcPs
                -> LHsBindsLR GhcRn GhcPs
                -> RnM (LHsBindsLR GhcRn GhcPs)
rnMethodBindLHS :: Bool
-> Name
-> LHsBindLR GhcPs GhcPs
-> LHsBindsLR GhcRn GhcPs
-> RnM (LHsBindsLR GhcRn GhcPs)
rnMethodBindLHS Bool
_ Name
cls (L SrcSpanAnnA
loc bind :: HsBind GhcPs
bind@(FunBind { fun_id :: forall idL idR. HsBindLR idL idR -> LIdP idL
fun_id = LIdP GhcPs
name })) LHsBindsLR GhcRn GhcPs
rest
  = SrcSpanAnnA
-> RnM (LHsBindsLR GhcRn GhcPs) -> RnM (LHsBindsLR GhcRn GhcPs)
forall ann a. EpAnn ann -> TcRn a -> TcRn a
setSrcSpanA SrcSpanAnnA
loc (RnM (LHsBindsLR GhcRn GhcPs) -> RnM (LHsBindsLR GhcRn GhcPs))
-> RnM (LHsBindsLR GhcRn GhcPs) -> RnM (LHsBindsLR GhcRn GhcPs)
forall a b. (a -> b) -> a -> b
$ do
    do { sel_name <- (RdrName -> TcM Name)
-> LocatedN RdrName -> RnM (GenLocated SrcSpanAnnN Name)
forall a b ann.
(a -> TcM b)
-> GenLocated (EpAnn ann) a -> TcRn (GenLocated (EpAnn ann) b)
wrapLocMA (Name -> SDoc -> RdrName -> TcM Name
lookupInstDeclBndr Name
cls (String -> SDoc
forall doc. IsLine doc => String -> doc
text String
"method")) LIdP GhcPs
LocatedN RdrName
name
                     -- We use the selector name as the binder
       ; let bind' = HsBind GhcPs
bind { fun_id = sel_name, fun_ext = noExtField }
       ; return (L loc bind' : rest ) }

-- Report error for all other forms of bindings
-- This is why we use a fold rather than map
rnMethodBindLHS Bool
is_cls_decl Name
_ (L SrcSpanAnnA
loc HsBind GhcPs
bind) LHsBindsLR GhcRn GhcPs
rest
  = do { SrcSpan -> TcRnMessage -> TcM ()
addErrAt (SrcSpanAnnA -> SrcSpan
forall a. HasLoc a => a -> SrcSpan
locA SrcSpanAnnA
loc) (TcRnMessage -> TcM ()) -> TcRnMessage -> TcM ()
forall a b. (a -> b) -> a -> b
$ DeclSort -> HsBind GhcPs -> TcRnMessage
TcRnIllegalClassBinding DeclSort
decl_sort HsBind GhcPs
bind
       ; [LocatedA (HsBindLR GhcRn GhcPs)]
-> IOEnv (Env TcGblEnv TcLclEnv) [LocatedA (HsBindLR GhcRn GhcPs)]
forall a. a -> IOEnv (Env TcGblEnv TcLclEnv) a
forall (m :: * -> *) a. Monad m => a -> m a
return LHsBindsLR GhcRn GhcPs
[LocatedA (HsBindLR GhcRn GhcPs)]
rest }
  where
    decl_sort :: DeclSort
decl_sort | Bool
is_cls_decl = DeclSort
ClassDeclSort
              | Bool
otherwise   = DeclSort
InstanceDeclSort

{-
************************************************************************
*                                                                      *
\subsubsection[dep-Sigs]{Signatures (and user-pragmas for values)}
*                                                                      *
************************************************************************

@renameSigs@ checks for:
\begin{enumerate}
\item more than one sig for one thing;
\item signatures given for things not bound here;
\end{enumerate}

At the moment we don't gather free-var info from the types in
signatures.  We'd only need this if we wanted to report unused tyvars.
-}

renameSigs :: HsSigCtxt
           -> [LSig GhcPs]
           -> RnM ([LSig GhcRn], FreeVars)
-- Renames the signatures and performs error checks
renameSigs :: HsSigCtxt
-> [XRec GhcPs (Sig GhcPs)] -> RnM ([LSig GhcRn], NameSet)
renameSigs HsSigCtxt
ctxt [XRec GhcPs (Sig GhcPs)]
sigs
  = do  { (NonEmpty (LocatedN RdrName, Sig GhcPs) -> TcM ())
-> [NonEmpty (LocatedN RdrName, Sig GhcPs)] -> TcM ()
forall (t :: * -> *) (m :: * -> *) a b.
(Foldable t, Monad m) =>
(a -> m b) -> t a -> m ()
mapM_ NonEmpty (LocatedN RdrName, Sig GhcPs) -> TcM ()
dupSigDeclErr ([XRec GhcPs (Sig GhcPs)]
-> [NonEmpty (LocatedN RdrName, Sig GhcPs)]
findDupSigs [XRec GhcPs (Sig GhcPs)]
sigs)

        ; [XRec GhcPs (Sig GhcPs)] -> TcM ()
checkDupMinimalSigs [XRec GhcPs (Sig GhcPs)]
sigs

        ; (sigs', sig_fvs) <- (GenLocated SrcSpanAnnA (Sig GhcPs)
 -> RnM (GenLocated SrcSpanAnnA (Sig GhcRn), NameSet))
-> [GenLocated SrcSpanAnnA (Sig GhcPs)]
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     ([GenLocated SrcSpanAnnA (Sig GhcRn)], NameSet)
forall (f :: * -> *) a b.
Traversable f =>
(a -> RnM (b, NameSet)) -> f a -> RnM (f b, NameSet)
mapFvRn ((Sig GhcPs -> TcM (Sig GhcRn, NameSet))
-> GenLocated SrcSpanAnnA (Sig GhcPs)
-> RnM (GenLocated SrcSpanAnnA (Sig GhcRn), NameSet)
forall a b c ann.
(a -> TcM (b, c))
-> GenLocated (EpAnn ann) a -> TcM (GenLocated (EpAnn ann) b, c)
wrapLocFstMA (HsSigCtxt -> Sig GhcPs -> TcM (Sig GhcRn, NameSet)
renameSig HsSigCtxt
ctxt)) [XRec GhcPs (Sig GhcPs)]
[GenLocated SrcSpanAnnA (Sig GhcPs)]
sigs

        ; let (good_sigs, bad_sigs) = partition (okHsSig ctxt) sigs'
        ; mapM_ misplacedSigErr bad_sigs                 -- Misplaced

        ; return (good_sigs, sig_fvs) }

----------------------
-- We use lookupSigOccRn in the signatures, which is a little bit unsatisfactory
-- because this won't work for:
--      instance Foo T where
--        {-# INLINE op #-}
--        Baz.op = ...
-- We'll just rename the INLINE prag to refer to whatever other 'op'
-- is in scope.  (I'm assuming that Baz.op isn't in scope unqualified.)
-- Doesn't seem worth much trouble to sort this.

renameSig :: HsSigCtxt -> Sig GhcPs -> RnM (Sig GhcRn, FreeVars)
renameSig :: HsSigCtxt -> Sig GhcPs -> TcM (Sig GhcRn, NameSet)
renameSig HsSigCtxt
ctxt sig :: Sig GhcPs
sig@(TypeSig XTypeSig GhcPs
_ [LIdP GhcPs]
vs LHsSigWcType GhcPs
ty)
  = do  { new_vs <- (LocatedN RdrName -> RnM (GenLocated SrcSpanAnnN Name))
-> [LocatedN RdrName]
-> IOEnv (Env TcGblEnv TcLclEnv) [GenLocated SrcSpanAnnN Name]
forall (t :: * -> *) (m :: * -> *) a b.
(Traversable t, Monad m) =>
(a -> m b) -> t a -> m (t b)
forall (m :: * -> *) a b. Monad m => (a -> m b) -> [a] -> m [b]
mapM (HsSigCtxt
-> Sig GhcPs
-> LocatedN RdrName
-> RnM (GenLocated SrcSpanAnnN Name)
lookupSigOccRnN HsSigCtxt
ctxt Sig GhcPs
sig) [LIdP GhcPs]
[LocatedN RdrName]
vs
        ; let doc = SDoc -> HsDocContext
TypeSigCtx ([LocatedN RdrName] -> SDoc
ppr_sig_bndrs [LIdP GhcPs]
[LocatedN RdrName]
vs)
        ; (new_ty, fvs) <- rnHsSigWcType doc ty
        ; return (TypeSig noAnn new_vs new_ty, fvs) }

renameSig HsSigCtxt
ctxt sig :: Sig GhcPs
sig@(ClassOpSig XClassOpSig GhcPs
_ Bool
is_deflt [LIdP GhcPs]
vs LHsSigType GhcPs
ty)
  = do  { defaultSigs_on <- Extension -> TcRnIf TcGblEnv TcLclEnv Bool
forall gbl lcl. Extension -> TcRnIf gbl lcl Bool
xoptM Extension
LangExt.DefaultSignatures
        ; when (is_deflt && not defaultSigs_on) $
          addErr (TcRnUnexpectedDefaultSig sig)
        ; new_v <- mapM (lookupSigOccRnN ctxt sig) vs
        ; (new_ty, fvs) <- rnHsSigType ty_ctxt TypeLevel ty
        ; return (ClassOpSig noAnn is_deflt new_v new_ty, fvs) }
  where
    (LIdP GhcPs
v1:[LIdP GhcPs]
_) = [LIdP GhcPs]
vs
    ty_ctxt :: HsDocContext
ty_ctxt = SDoc -> HsDocContext
GenericCtx (String -> SDoc
forall doc. IsLine doc => String -> doc
text String
"a class method signature for"
                          SDoc -> SDoc -> SDoc
forall doc. IsLine doc => doc -> doc -> doc
<+> SDoc -> SDoc
quotes (LocatedN RdrName -> SDoc
forall a. Outputable a => a -> SDoc
ppr LIdP GhcPs
LocatedN RdrName
v1))

renameSig HsSigCtxt
_ (SpecInstSig ([AddEpAnn]
_, SourceText
src) LHsSigType GhcPs
ty)
  = do  { HsDocContext -> LHsSigType GhcPs -> TcM ()
checkInferredVars HsDocContext
doc LHsSigType GhcPs
ty
        ; (new_ty, fvs) <- HsDocContext
-> TypeOrKind
-> LHsSigType GhcPs
-> RnM (LHsSigType GhcRn, NameSet)
rnHsSigType HsDocContext
doc TypeOrKind
TypeLevel LHsSigType GhcPs
ty
          -- Check if there are any nested `forall`s or contexts, which are
          -- illegal in the type of an instance declaration (see
          -- Note [No nested foralls or contexts in instance types] in
          -- GHC.Hs.Type).
        ; addNoNestedForallsContextsErr doc NFC_Specialize
            (getLHsInstDeclHead new_ty)
        ; return (SpecInstSig (noAnn, src) new_ty,fvs) }
  where
    doc :: HsDocContext
doc = HsDocContext
SpecInstSigCtx

-- {-# SPECIALISE #-} pragmas can refer to imported Ids
-- so, in the top-level case (when mb_names is Nothing)
-- we use lookupOccRn.  If there's both an imported and a local 'f'
-- then the SPECIALISE pragma is ambiguous, unlike all other signatures
renameSig HsSigCtxt
ctxt sig :: Sig GhcPs
sig@(SpecSig XSpecSig GhcPs
_ LIdP GhcPs
v [LHsSigType GhcPs]
tys InlinePragma
inl)
  = do  { new_v <- case HsSigCtxt
ctxt of
                     TopSigCtxt {} -> LocatedN RdrName -> RnM (GenLocated SrcSpanAnnN Name)
forall {ann}.
GenLocated (EpAnn ann) RdrName
-> TcRn (GenLocated (EpAnn ann) Name)
lookupLocatedOccRn LIdP GhcPs
LocatedN RdrName
v
                     HsSigCtxt
_             -> HsSigCtxt
-> Sig GhcPs
-> LocatedN RdrName
-> RnM (GenLocated SrcSpanAnnN Name)
lookupSigOccRnN HsSigCtxt
ctxt Sig GhcPs
sig LIdP GhcPs
LocatedN RdrName
v
        ; (new_ty, fvs) <- foldM do_one ([],emptyFVs) tys
        ; return (SpecSig noAnn new_v new_ty inl, fvs) }
  where
    ty_ctxt :: HsDocContext
ty_ctxt = SDoc -> HsDocContext
GenericCtx (String -> SDoc
forall doc. IsLine doc => String -> doc
text String
"a SPECIALISE signature for"
                          SDoc -> SDoc -> SDoc
forall doc. IsLine doc => doc -> doc -> doc
<+> SDoc -> SDoc
quotes (LocatedN RdrName -> SDoc
forall a. Outputable a => a -> SDoc
ppr LIdP GhcPs
LocatedN RdrName
v))
    do_one :: ([GenLocated SrcSpanAnnA (HsSigType GhcRn)], NameSet)
-> GenLocated SrcSpanAnnA (HsSigType GhcPs)
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     ([GenLocated SrcSpanAnnA (HsSigType GhcRn)], NameSet)
do_one ([GenLocated SrcSpanAnnA (HsSigType GhcRn)]
tys,NameSet
fvs) GenLocated SrcSpanAnnA (HsSigType GhcPs)
ty
      = do { (new_ty, fvs_ty) <- HsDocContext
-> TypeOrKind
-> LHsSigType GhcPs
-> RnM (LHsSigType GhcRn, NameSet)
rnHsSigType HsDocContext
ty_ctxt TypeOrKind
TypeLevel LHsSigType GhcPs
GenLocated SrcSpanAnnA (HsSigType GhcPs)
ty
           ; return ( new_ty:tys, fvs_ty `plusFV` fvs) }

renameSig HsSigCtxt
ctxt sig :: Sig GhcPs
sig@(InlineSig XInlineSig GhcPs
_ LIdP GhcPs
v InlinePragma
s)
  = do  { new_v <- HsSigCtxt
-> Sig GhcPs
-> LocatedN RdrName
-> RnM (GenLocated SrcSpanAnnN Name)
lookupSigOccRnN HsSigCtxt
ctxt Sig GhcPs
sig LIdP GhcPs
LocatedN RdrName
v
        ; return (InlineSig noAnn new_v s, emptyFVs) }

renameSig HsSigCtxt
ctxt (FixSig XFixSig GhcPs
_ FixitySig GhcPs
fsig)
  = do  { new_fsig <- HsSigCtxt -> FixitySig GhcPs -> RnM (FixitySig GhcRn)
rnSrcFixityDecl HsSigCtxt
ctxt FixitySig GhcPs
fsig
        ; return (FixSig noAnn new_fsig, emptyFVs) }

renameSig HsSigCtxt
ctxt sig :: Sig GhcPs
sig@(MinimalSig ([AddEpAnn]
_, SourceText
s) (L SrcSpanAnnL
l BooleanFormula (LIdP GhcPs)
bf))
  = do new_bf <- (LocatedN RdrName -> RnM (GenLocated SrcSpanAnnN Name))
-> BooleanFormula (LocatedN RdrName)
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     (BooleanFormula (GenLocated SrcSpanAnnN Name))
forall (t :: * -> *) (f :: * -> *) a b.
(Traversable t, Applicative f) =>
(a -> f b) -> t a -> f (t b)
forall (f :: * -> *) a b.
Applicative f =>
(a -> f b) -> BooleanFormula a -> f (BooleanFormula b)
traverse (HsSigCtxt
-> Sig GhcPs
-> LocatedN RdrName
-> RnM (GenLocated SrcSpanAnnN Name)
lookupSigOccRnN HsSigCtxt
ctxt Sig GhcPs
sig) BooleanFormula (LIdP GhcPs)
BooleanFormula (LocatedN RdrName)
bf
       return (MinimalSig (noAnn, s) (L l new_bf), emptyFVs)

renameSig HsSigCtxt
ctxt sig :: Sig GhcPs
sig@(PatSynSig XPatSynSig GhcPs
_ [LIdP GhcPs]
vs LHsSigType GhcPs
ty)
  = do  { new_vs <- (LocatedN RdrName -> RnM (GenLocated SrcSpanAnnN Name))
-> [LocatedN RdrName]
-> IOEnv (Env TcGblEnv TcLclEnv) [GenLocated SrcSpanAnnN Name]
forall (t :: * -> *) (m :: * -> *) a b.
(Traversable t, Monad m) =>
(a -> m b) -> t a -> m (t b)
forall (m :: * -> *) a b. Monad m => (a -> m b) -> [a] -> m [b]
mapM (HsSigCtxt
-> Sig GhcPs
-> LocatedN RdrName
-> RnM (GenLocated SrcSpanAnnN Name)
lookupSigOccRnN HsSigCtxt
ctxt Sig GhcPs
sig) [LIdP GhcPs]
[LocatedN RdrName]
vs
        ; (ty', fvs) <- rnHsSigType ty_ctxt TypeLevel ty
        ; return (PatSynSig noAnn new_vs ty', fvs) }
  where
    ty_ctxt :: HsDocContext
ty_ctxt = SDoc -> HsDocContext
GenericCtx (String -> SDoc
forall doc. IsLine doc => String -> doc
text String
"a pattern synonym signature for"
                          SDoc -> SDoc -> SDoc
forall doc. IsLine doc => doc -> doc -> doc
<+> [LocatedN RdrName] -> SDoc
ppr_sig_bndrs [LIdP GhcPs]
[LocatedN RdrName]
vs)

renameSig HsSigCtxt
ctxt sig :: Sig GhcPs
sig@(SCCFunSig ([AddEpAnn]
_, SourceText
st) LIdP GhcPs
v Maybe (XRec GhcPs StringLiteral)
s)
  = do  { new_v <- HsSigCtxt
-> Sig GhcPs
-> LocatedN RdrName
-> RnM (GenLocated SrcSpanAnnN Name)
lookupSigOccRnN HsSigCtxt
ctxt Sig GhcPs
sig LIdP GhcPs
LocatedN RdrName
v
        ; return (SCCFunSig (noAnn, st) new_v s, emptyFVs) }

-- COMPLETE Sigs can refer to imported IDs which is why we use
-- lookupLocatedOccRn rather than lookupSigOccRn
renameSig HsSigCtxt
_ctxt sig :: Sig GhcPs
sig@(CompleteMatchSig ([AddEpAnn]
_, SourceText
s) [LIdP GhcPs]
bf Maybe (LIdP GhcPs)
mty)
  = do new_bf <- (LocatedN RdrName -> RnM (GenLocated SrcSpanAnnN Name))
-> [LocatedN RdrName]
-> IOEnv (Env TcGblEnv TcLclEnv) [GenLocated SrcSpanAnnN Name]
forall (t :: * -> *) (f :: * -> *) a b.
(Traversable t, Applicative f) =>
(a -> f b) -> t a -> f (t b)
forall (f :: * -> *) a b.
Applicative f =>
(a -> f b) -> [a] -> f [b]
traverse LocatedN RdrName -> RnM (GenLocated SrcSpanAnnN Name)
forall {ann}.
GenLocated (EpAnn ann) RdrName
-> TcRn (GenLocated (EpAnn ann) Name)
lookupLocatedOccRn [LIdP GhcPs]
[LocatedN RdrName]
bf
       new_mty  <- traverse lookupLocatedOccRn mty

       this_mod <- fmap tcg_mod getGblEnv
       unless (any (nameIsLocalOrFrom this_mod . unLoc) new_bf) $
         -- Why 'any'? See Note [Orphan COMPLETE pragmas]
         addErrCtxt (text "In" <+> ppr sig) $ failWithTc TcRnOrphanCompletePragma

       return (CompleteMatchSig (noAnn, s) new_bf new_mty, emptyFVs)


{-
Note [Orphan COMPLETE pragmas]
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
We define a COMPLETE pragma to be a non-orphan if it includes at least
one conlike defined in the current module. Why is this sufficient?
Well if you have a pattern match

  case expr of
    P1 -> ...
    P2 -> ...
    P3 -> ...

any COMPLETE pragma which mentions a conlike other than P1, P2 or P3
will not be of any use in verifying that the pattern match is
exhaustive. So as we have certainly read the interface files that
define P1, P2 and P3, we will have loaded all non-orphan COMPLETE
pragmas that could be relevant to this pattern match.

For now we simply disallow orphan COMPLETE pragmas, as the added
complexity of supporting them properly doesn't seem worthwhile.
-}

ppr_sig_bndrs :: [LocatedN RdrName] -> SDoc
ppr_sig_bndrs :: [LocatedN RdrName] -> SDoc
ppr_sig_bndrs [LocatedN RdrName]
bs = SDoc -> SDoc
quotes ((LocatedN RdrName -> SDoc) -> [LocatedN RdrName] -> SDoc
forall a. (a -> SDoc) -> [a] -> SDoc
pprWithCommas LocatedN RdrName -> SDoc
forall a. Outputable a => a -> SDoc
ppr [LocatedN RdrName]
bs)

okHsSig :: HsSigCtxt -> LSig (GhcPass a) -> Bool
okHsSig :: forall (a :: Pass). HsSigCtxt -> LSig (GhcPass a) -> Bool
okHsSig HsSigCtxt
ctxt (L SrcSpanAnnA
_ Sig (GhcPass a)
sig)
  = case (Sig (GhcPass a)
sig, HsSigCtxt
ctxt) of
     (ClassOpSig {}, ClsDeclCtxt {})  -> Bool
True
     (ClassOpSig {}, InstDeclCtxt {}) -> Bool
True
     (ClassOpSig {}, HsSigCtxt
_)               -> Bool
False

     (TypeSig {}, ClsDeclCtxt {})  -> Bool
False
     (TypeSig {}, InstDeclCtxt {}) -> Bool
False
     (TypeSig {}, HsSigCtxt
_)               -> Bool
True

     (PatSynSig {}, TopSigCtxt{}) -> Bool
True
     (PatSynSig {}, HsSigCtxt
_)            -> Bool
False

     (FixSig {}, InstDeclCtxt {}) -> Bool
False
     (FixSig {}, HsSigCtxt
_)               -> Bool
True

     (InlineSig {}, HsBootCtxt {}) -> Bool
False
     (InlineSig {}, HsSigCtxt
_)             -> Bool
True

     (SpecSig {}, TopSigCtxt {})    -> Bool
True
     (SpecSig {}, LocalBindCtxt {}) -> Bool
True
     (SpecSig {}, InstDeclCtxt {})  -> Bool
True
     (SpecSig {}, HsSigCtxt
_)                -> Bool
False

     (SpecInstSig {}, InstDeclCtxt {}) -> Bool
True
     (SpecInstSig {}, HsSigCtxt
_)               -> Bool
False

     (MinimalSig {}, ClsDeclCtxt {}) -> Bool
True
     (MinimalSig {}, HsSigCtxt
_)              -> Bool
False

     (SCCFunSig {}, HsBootCtxt {}) -> Bool
False
     (SCCFunSig {}, HsSigCtxt
_)             -> Bool
True

     (CompleteMatchSig {}, TopSigCtxt {} ) -> Bool
True
     (CompleteMatchSig {}, HsSigCtxt
_)              -> Bool
False

     (XSig {}, TopSigCtxt {})   -> Bool
True
     (XSig {}, InstDeclCtxt {}) -> Bool
True
     (XSig {}, HsSigCtxt
_)               -> Bool
False


-------------------
findDupSigs :: [LSig GhcPs] -> [NonEmpty (LocatedN RdrName, Sig GhcPs)]
-- Check for duplicates on RdrName version,
-- because renamed version has unboundName for
-- not-in-scope binders, which gives bogus dup-sig errors
-- NB: in a class decl, a 'generic' sig is not considered
--     equal to an ordinary sig, so we allow, say
--           class C a where
--             op :: a -> a
--             default op :: Eq a => a -> a
findDupSigs :: [XRec GhcPs (Sig GhcPs)]
-> [NonEmpty (LocatedN RdrName, Sig GhcPs)]
findDupSigs [XRec GhcPs (Sig GhcPs)]
sigs
  = ((LocatedN RdrName, Sig GhcPs)
 -> (LocatedN RdrName, Sig GhcPs) -> Bool)
-> [(LocatedN RdrName, Sig GhcPs)]
-> [NonEmpty (LocatedN RdrName, Sig GhcPs)]
forall a. (a -> a -> Bool) -> [a] -> [NonEmpty a]
findDupsEq (LocatedN RdrName, Sig GhcPs)
-> (LocatedN RdrName, Sig GhcPs) -> Bool
matching_sig ((GenLocated SrcSpanAnnA (Sig GhcPs)
 -> [(LocatedN RdrName, Sig GhcPs)])
-> [GenLocated SrcSpanAnnA (Sig GhcPs)]
-> [(LocatedN RdrName, Sig GhcPs)]
forall (t :: * -> *) a b. Foldable t => (a -> [b]) -> t a -> [b]
concatMap (Sig GhcPs -> [(LocatedN RdrName, Sig GhcPs)]
expand_sig (Sig GhcPs -> [(LocatedN RdrName, Sig GhcPs)])
-> (GenLocated SrcSpanAnnA (Sig GhcPs) -> Sig GhcPs)
-> GenLocated SrcSpanAnnA (Sig GhcPs)
-> [(LocatedN RdrName, Sig GhcPs)]
forall b c a. (b -> c) -> (a -> b) -> a -> c
. GenLocated SrcSpanAnnA (Sig GhcPs) -> Sig GhcPs
forall l e. GenLocated l e -> e
unLoc) [XRec GhcPs (Sig GhcPs)]
[GenLocated SrcSpanAnnA (Sig GhcPs)]
sigs)
  where
    expand_sig :: Sig GhcPs -> [(LocatedN RdrName, Sig GhcPs)] -- AZ
    expand_sig :: Sig GhcPs -> [(LocatedN RdrName, Sig GhcPs)]
expand_sig sig :: Sig GhcPs
sig@(FixSig XFixSig GhcPs
_ (FixitySig XFixitySig GhcPs
_ [LIdP GhcPs]
ns Fixity
_)) = [LocatedN RdrName]
-> [Sig GhcPs] -> [(LocatedN RdrName, Sig GhcPs)]
forall a b. [a] -> [b] -> [(a, b)]
zip [LIdP GhcPs]
[LocatedN RdrName]
ns (Sig GhcPs -> [Sig GhcPs]
forall a. a -> [a]
repeat Sig GhcPs
sig)
    expand_sig sig :: Sig GhcPs
sig@(InlineSig XInlineSig GhcPs
_ LIdP GhcPs
n InlinePragma
_)             = [(LIdP GhcPs
LocatedN RdrName
n,Sig GhcPs
sig)]
    expand_sig sig :: Sig GhcPs
sig@(TypeSig XTypeSig GhcPs
_ [LIdP GhcPs]
ns LHsSigWcType GhcPs
_)              = [(LocatedN RdrName
n,Sig GhcPs
sig) | LocatedN RdrName
n <- [LIdP GhcPs]
[LocatedN RdrName]
ns]
    expand_sig sig :: Sig GhcPs
sig@(ClassOpSig XClassOpSig GhcPs
_ Bool
_ [LIdP GhcPs]
ns LHsSigType GhcPs
_)         = [(LocatedN RdrName
n,Sig GhcPs
sig) | LocatedN RdrName
n <- [LIdP GhcPs]
[LocatedN RdrName]
ns]
    expand_sig sig :: Sig GhcPs
sig@(PatSynSig XPatSynSig GhcPs
_ [LIdP GhcPs]
ns  LHsSigType GhcPs
_ )          = [(LocatedN RdrName
n,Sig GhcPs
sig) | LocatedN RdrName
n <- [LIdP GhcPs]
[LocatedN RdrName]
ns]
    expand_sig sig :: Sig GhcPs
sig@(SCCFunSig ([AddEpAnn]
_, SourceText
_) LIdP GhcPs
n Maybe (XRec GhcPs StringLiteral)
_)           = [(LIdP GhcPs
LocatedN RdrName
n,Sig GhcPs
sig)]
    expand_sig Sig GhcPs
_ = []

    matching_sig :: (LocatedN RdrName, Sig GhcPs) -> (LocatedN RdrName, Sig GhcPs) -> Bool --AZ
    matching_sig :: (LocatedN RdrName, Sig GhcPs)
-> (LocatedN RdrName, Sig GhcPs) -> Bool
matching_sig (L SrcSpanAnnN
_ RdrName
n1,Sig GhcPs
sig1) (L SrcSpanAnnN
_ RdrName
n2,Sig GhcPs
sig2)       = RdrName
n1 RdrName -> RdrName -> Bool
forall a. Eq a => a -> a -> Bool
== RdrName
n2 Bool -> Bool -> Bool
&& Sig GhcPs -> Sig GhcPs -> Bool
forall {pass} {pass}. Sig pass -> Sig pass -> Bool
mtch Sig GhcPs
sig1 Sig GhcPs
sig2
    mtch :: Sig pass -> Sig pass -> Bool
mtch (FixSig {})           (FixSig {})         = Bool
True
    mtch (InlineSig {})        (InlineSig {})      = Bool
True
    mtch (TypeSig {})          (TypeSig {})        = Bool
True
    mtch (ClassOpSig XClassOpSig pass
_ Bool
d1 [LIdP pass]
_ LHsSigType pass
_) (ClassOpSig XClassOpSig pass
_ Bool
d2 [LIdP pass]
_ LHsSigType pass
_) = Bool
d1 Bool -> Bool -> Bool
forall a. Eq a => a -> a -> Bool
== Bool
d2
    mtch (PatSynSig XPatSynSig pass
_ [LIdP pass]
_ LHsSigType pass
_)     (PatSynSig XPatSynSig pass
_ [LIdP pass]
_ LHsSigType pass
_)   = Bool
True
    mtch (SCCFunSig{})         (SCCFunSig{})       = Bool
True
    mtch Sig pass
_ Sig pass
_ = Bool
False

-- Warn about multiple MINIMAL signatures
checkDupMinimalSigs :: [LSig GhcPs] -> RnM ()
checkDupMinimalSigs :: [XRec GhcPs (Sig GhcPs)] -> TcM ()
checkDupMinimalSigs [XRec GhcPs (Sig GhcPs)]
sigs
  = case (XRec GhcPs (Sig GhcPs) -> Bool)
-> [XRec GhcPs (Sig GhcPs)] -> [XRec GhcPs (Sig GhcPs)]
forall a. (a -> Bool) -> [a] -> [a]
filter XRec GhcPs (Sig GhcPs) -> Bool
forall p. UnXRec p => LSig p -> Bool
isMinimalLSig [XRec GhcPs (Sig GhcPs)]
sigs of
      XRec GhcPs (Sig GhcPs)
sig1 : XRec GhcPs (Sig GhcPs)
sig2 : [XRec GhcPs (Sig GhcPs)]
otherSigs -> XRec GhcPs (Sig GhcPs)
-> XRec GhcPs (Sig GhcPs) -> [XRec GhcPs (Sig GhcPs)] -> TcM ()
dupMinimalSigErr XRec GhcPs (Sig GhcPs)
sig1 XRec GhcPs (Sig GhcPs)
sig2 [XRec GhcPs (Sig GhcPs)]
otherSigs
      [XRec GhcPs (Sig GhcPs)]
_ -> () -> TcM ()
forall a. a -> IOEnv (Env TcGblEnv TcLclEnv) a
forall (m :: * -> *) a. Monad m => a -> m a
return ()

localCompletePragmas :: [LSig GhcRn] -> CompleteMatches
localCompletePragmas :: [LSig GhcRn] -> CompleteMatches
localCompletePragmas [LSig GhcRn]
sigs = (GenLocated SrcSpanAnnA (Sig GhcRn) -> Maybe CompleteMatch)
-> [GenLocated SrcSpanAnnA (Sig GhcRn)] -> CompleteMatches
forall a b. (a -> Maybe b) -> [a] -> [b]
mapMaybe (Sig GhcRn -> Maybe (CompleteMatchX (IdP GhcRn))
Sig GhcRn -> Maybe CompleteMatch
getCompleteSig (Sig GhcRn -> Maybe CompleteMatch)
-> (GenLocated SrcSpanAnnA (Sig GhcRn) -> Sig GhcRn)
-> GenLocated SrcSpanAnnA (Sig GhcRn)
-> Maybe CompleteMatch
forall b c a. (b -> c) -> (a -> b) -> a -> c
. GenLocated SrcSpanAnnA (Sig GhcRn) -> Sig GhcRn
forall l e. GenLocated l e -> e
unLoc) ([GenLocated SrcSpanAnnA (Sig GhcRn)] -> CompleteMatches)
-> [GenLocated SrcSpanAnnA (Sig GhcRn)] -> CompleteMatches
forall a b. (a -> b) -> a -> b
$ [GenLocated SrcSpanAnnA (Sig GhcRn)]
-> [GenLocated SrcSpanAnnA (Sig GhcRn)]
forall a. [a] -> [a]
reverse [LSig GhcRn]
[GenLocated SrcSpanAnnA (Sig GhcRn)]
sigs
  where
    getCompleteSig :: Sig GhcRn -> Maybe (CompleteMatchX (IdP GhcRn))
getCompleteSig = \case
      CompleteMatchSig XCompleteMatchSig GhcRn
_ [XRec GhcRn (IdP GhcRn)]
cons Maybe (XRec GhcRn (IdP GhcRn))
mbTyCon ->
        CompleteMatchX (IdP GhcRn) -> Maybe (CompleteMatchX (IdP GhcRn))
forall a. a -> Maybe a
Just (CompleteMatchX (IdP GhcRn) -> Maybe (CompleteMatchX (IdP GhcRn)))
-> CompleteMatchX (IdP GhcRn) -> Maybe (CompleteMatchX (IdP GhcRn))
forall a b. (a -> b) -> a -> b
$ UniqDSet (IdP GhcRn) -> Maybe Name -> CompleteMatchX (IdP GhcRn)
forall con. UniqDSet con -> Maybe Name -> CompleteMatchX con
CompleteMatch ([IdP GhcRn] -> UniqDSet (IdP GhcRn)
forall a. Uniquable a => [a] -> UniqDSet a
mkUniqDSet ([IdP GhcRn] -> UniqDSet (IdP GhcRn))
-> [IdP GhcRn] -> UniqDSet (IdP GhcRn)
forall a b. (a -> b) -> a -> b
$ (GenLocated SrcSpanAnnN (IdP GhcRn) -> IdP GhcRn)
-> [GenLocated SrcSpanAnnN (IdP GhcRn)] -> [IdP GhcRn]
forall a b. (a -> b) -> [a] -> [b]
map GenLocated SrcSpanAnnN (IdP GhcRn) -> IdP GhcRn
forall l e. GenLocated l e -> e
unLoc [XRec GhcRn (IdP GhcRn)]
[GenLocated SrcSpanAnnN (IdP GhcRn)]
cons) ((GenLocated SrcSpanAnnN Name -> Name)
-> Maybe (GenLocated SrcSpanAnnN Name) -> Maybe Name
forall a b. (a -> b) -> Maybe a -> Maybe b
forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
fmap GenLocated SrcSpanAnnN Name -> Name
forall l e. GenLocated l e -> e
unLoc Maybe (XRec GhcRn (IdP GhcRn))
Maybe (GenLocated SrcSpanAnnN Name)
mbTyCon)
      Sig GhcRn
_ -> Maybe (CompleteMatchX (IdP GhcRn))
forall a. Maybe a
Nothing
  -- SG: for some reason I haven't investigated further, the signatures come in
  -- backwards wrt. declaration order. So we reverse them here, because it makes
  -- a difference for incomplete match suggestions.


{-
************************************************************************
*                                                                      *
\subsection{Match}
*                                                                      *
************************************************************************
-}

type AnnoBody body
  = ( Anno [LocatedA (Match GhcRn (LocatedA (body GhcRn)))] ~ SrcSpanAnnL
    , Anno [LocatedA (Match GhcPs (LocatedA (body GhcPs)))] ~ SrcSpanAnnL
    , Anno (Match GhcRn (LocatedA (body GhcRn))) ~ SrcSpanAnnA
    , Anno (Match GhcPs (LocatedA (body GhcPs))) ~ SrcSpanAnnA
    , Anno (GRHS GhcRn (LocatedA (body GhcRn))) ~ EpAnnCO
    , Anno (GRHS GhcPs (LocatedA (body GhcPs))) ~ EpAnnCO
    , Outputable (body GhcPs)
    )

-- Note [Empty MatchGroups]
-- ~~~~~~~~~~~~~~~~~~~~~~~~
-- In some cases, MatchGroups are allowed to be empty. Firstly, the
-- prerequisite is that -XEmptyCase is enabled. Then you have an empty
-- MatchGroup resulting either from a case-expression:
--
--     case e of {}
--
-- or from a \case-expression:
--
--     \case {}
--
-- NB: \cases {} is not allowed, since it's not clear how many patterns this
-- should match on.
--
-- The same applies in arrow notation commands: With -XEmptyCases, it is
-- allowed in case- and \case-commands, but not \cases.
--
-- Since the lambda expressions and empty function definitions are already
-- disallowed elsewhere, here, we only need to make sure we don't accept empty
-- \cases expressions or commands. In that case, or if we encounter an empty
-- MatchGroup but -XEmptyCases is disabled, we add an error.

rnMatchGroup :: (Outputable (body GhcPs), AnnoBody body) => HsMatchContextRn
             -> (LocatedA (body GhcPs) -> RnM (LocatedA (body GhcRn), FreeVars))
             -> MatchGroup GhcPs (LocatedA (body GhcPs))
             -> RnM (MatchGroup GhcRn (LocatedA (body GhcRn)), FreeVars)
rnMatchGroup :: forall (body :: * -> *).
(Outputable (body GhcPs), AnnoBody body) =>
HsMatchContextRn
-> (LocatedA (body GhcPs) -> RnM (LocatedA (body GhcRn), NameSet))
-> MatchGroup GhcPs (LocatedA (body GhcPs))
-> RnM (MatchGroup GhcRn (LocatedA (body GhcRn)), NameSet)
rnMatchGroup HsMatchContextRn
ctxt LocatedA (body GhcPs) -> RnM (LocatedA (body GhcRn), NameSet)
rnBody (MG { mg_alts :: forall p body. MatchGroup p body -> XRec p [LMatch p body]
mg_alts = L SrcSpanAnnL
lm [LocatedA (Match GhcPs (LocatedA (body GhcPs)))]
ms, mg_ext :: forall p body. MatchGroup p body -> XMG p body
mg_ext = XMG GhcPs (LocatedA (body GhcPs))
origin })
         -- see Note [Empty MatchGroups]
  = do { TcRnIf TcGblEnv TcLclEnv Bool -> TcM () -> TcM ()
forall (m :: * -> *). Monad m => m Bool -> m () -> m ()
whenM (([LocatedA (Match GhcPs (LocatedA (body GhcPs)))] -> Bool
forall a. [a] -> Bool
forall (t :: * -> *) a. Foldable t => t a -> Bool
null [LocatedA (Match GhcPs (LocatedA (body GhcPs)))]
ms Bool -> Bool -> Bool
&&) (Bool -> Bool)
-> TcRnIf TcGblEnv TcLclEnv Bool -> TcRnIf TcGblEnv TcLclEnv Bool
forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
<$> TcRnIf TcGblEnv TcLclEnv Bool
mustn't_be_empty) (TcRnMessage -> TcM ()
addErr (HsMatchContextRn -> TcRnMessage
TcRnEmptyCase HsMatchContextRn
ctxt))
       ; (new_ms, ms_fvs) <- (LocatedA (Match GhcPs (LocatedA (body GhcPs)))
 -> RnM (LocatedA (Match GhcRn (LocatedA (body GhcRn))), NameSet))
-> [LocatedA (Match GhcPs (LocatedA (body GhcPs)))]
-> RnM ([LocatedA (Match GhcRn (LocatedA (body GhcRn)))], NameSet)
forall (f :: * -> *) a b.
Traversable f =>
(a -> RnM (b, NameSet)) -> f a -> RnM (f b, NameSet)
mapFvRn (HsMatchContextRn
-> (LocatedA (body GhcPs) -> RnM (LocatedA (body GhcRn), NameSet))
-> LMatch GhcPs (LocatedA (body GhcPs))
-> RnM (LMatch GhcRn (LocatedA (body GhcRn)), NameSet)
forall (body :: * -> *).
AnnoBody body =>
HsMatchContextRn
-> (LocatedA (body GhcPs) -> RnM (LocatedA (body GhcRn), NameSet))
-> LMatch GhcPs (LocatedA (body GhcPs))
-> RnM (LMatch GhcRn (LocatedA (body GhcRn)), NameSet)
rnMatch HsMatchContextRn
ctxt LocatedA (body GhcPs) -> RnM (LocatedA (body GhcRn), NameSet)
rnBody) [LocatedA (Match GhcPs (LocatedA (body GhcPs)))]
ms
       ; return (mkMatchGroup origin (L lm new_ms), ms_fvs) }
  where
    mustn't_be_empty :: TcRnIf TcGblEnv TcLclEnv Bool
mustn't_be_empty = case HsMatchContextRn
ctxt of
      LamAlt HsLamVariant
LamCases -> Bool -> TcRnIf TcGblEnv TcLclEnv Bool
forall a. a -> IOEnv (Env TcGblEnv TcLclEnv) a
forall (m :: * -> *) a. Monad m => a -> m a
return Bool
True
      ArrowMatchCtxt (ArrowLamAlt HsLamVariant
LamCases) -> Bool -> TcRnIf TcGblEnv TcLclEnv Bool
forall a. a -> IOEnv (Env TcGblEnv TcLclEnv) a
forall (m :: * -> *) a. Monad m => a -> m a
return Bool
True
      HsMatchContextRn
_ -> Bool -> Bool
not (Bool -> Bool)
-> TcRnIf TcGblEnv TcLclEnv Bool -> TcRnIf TcGblEnv TcLclEnv Bool
forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
<$> Extension -> TcRnIf TcGblEnv TcLclEnv Bool
forall gbl lcl. Extension -> TcRnIf gbl lcl Bool
xoptM Extension
LangExt.EmptyCase

rnMatch :: AnnoBody body
        => HsMatchContextRn
        -> (LocatedA (body GhcPs) -> RnM (LocatedA (body GhcRn), FreeVars))
        -> LMatch GhcPs (LocatedA (body GhcPs))
        -> RnM (LMatch GhcRn (LocatedA (body GhcRn)), FreeVars)
rnMatch :: forall (body :: * -> *).
AnnoBody body =>
HsMatchContextRn
-> (LocatedA (body GhcPs) -> RnM (LocatedA (body GhcRn), NameSet))
-> LMatch GhcPs (LocatedA (body GhcPs))
-> RnM (LMatch GhcRn (LocatedA (body GhcRn)), NameSet)
rnMatch HsMatchContextRn
ctxt LocatedA (body GhcPs) -> RnM (LocatedA (body GhcRn), NameSet)
rnBody = (Match GhcPs (LocatedA (body GhcPs))
 -> TcM (Match GhcRn (LocatedA (body GhcRn)), NameSet))
-> LocatedA (Match GhcPs (LocatedA (body GhcPs)))
-> TcM (LocatedA (Match GhcRn (LocatedA (body GhcRn))), NameSet)
forall a b c ann.
(a -> TcM (b, c))
-> GenLocated (EpAnn ann) a -> TcM (GenLocated (EpAnn ann) b, c)
wrapLocFstMA (HsMatchContextRn
-> (LocatedA (body GhcPs) -> RnM (LocatedA (body GhcRn), NameSet))
-> Match GhcPs (LocatedA (body GhcPs))
-> TcM (Match GhcRn (LocatedA (body GhcRn)), NameSet)
forall (body :: * -> *).
AnnoBody body =>
HsMatchContextRn
-> (LocatedA (body GhcPs) -> RnM (LocatedA (body GhcRn), NameSet))
-> Match GhcPs (LocatedA (body GhcPs))
-> RnM (Match GhcRn (LocatedA (body GhcRn)), NameSet)
rnMatch' HsMatchContextRn
ctxt LocatedA (body GhcPs) -> RnM (LocatedA (body GhcRn), NameSet)
rnBody)

rnMatch' :: (AnnoBody body)
         => HsMatchContextRn
         -> (LocatedA (body GhcPs) -> RnM (LocatedA (body GhcRn), FreeVars))
         -> Match GhcPs (LocatedA (body GhcPs))
         -> RnM (Match GhcRn (LocatedA (body GhcRn)), FreeVars)
rnMatch' :: forall (body :: * -> *).
AnnoBody body =>
HsMatchContextRn
-> (LocatedA (body GhcPs) -> RnM (LocatedA (body GhcRn), NameSet))
-> Match GhcPs (LocatedA (body GhcPs))
-> RnM (Match GhcRn (LocatedA (body GhcRn)), NameSet)
rnMatch' HsMatchContextRn
ctxt LocatedA (body GhcPs) -> RnM (LocatedA (body GhcRn), NameSet)
rnBody (Match { m_ctxt :: forall p body. Match p body -> HsMatchContext (LIdP (NoGhcTc p))
m_ctxt = HsMatchContext (LIdP (NoGhcTc GhcPs))
mf, m_pats :: forall p body. Match p body -> XRec p [LPat p]
m_pats = L EpaLocation
l [GenLocated SrcSpanAnnA (Pat GhcPs)]
pats, m_grhss :: forall p body. Match p body -> GRHSs p body
m_grhss = GRHSs GhcPs (LocatedA (body GhcPs))
grhss })
  = HsMatchContextRn
-> [LPat GhcPs]
-> ([LPat GhcRn]
    -> RnM (Match GhcRn (LocatedA (body GhcRn)), NameSet))
-> RnM (Match GhcRn (LocatedA (body GhcRn)), NameSet)
forall a.
HsMatchContextRn
-> [LPat GhcPs]
-> ([LPat GhcRn] -> RnM (a, NameSet))
-> RnM (a, NameSet)
rnPats HsMatchContextRn
ctxt [LPat GhcPs]
[GenLocated SrcSpanAnnA (Pat GhcPs)]
pats (([LPat GhcRn]
  -> RnM (Match GhcRn (LocatedA (body GhcRn)), NameSet))
 -> RnM (Match GhcRn (LocatedA (body GhcRn)), NameSet))
-> ([LPat GhcRn]
    -> RnM (Match GhcRn (LocatedA (body GhcRn)), NameSet))
-> RnM (Match GhcRn (LocatedA (body GhcRn)), NameSet)
forall a b. (a -> b) -> a -> b
$ \ [LPat GhcRn]
pats' -> do
        { (grhss', grhss_fvs) <- HsMatchContextRn
-> (LocatedA (body GhcPs) -> RnM (LocatedA (body GhcRn), NameSet))
-> GRHSs GhcPs (LocatedA (body GhcPs))
-> RnM (GRHSs GhcRn (LocatedA (body GhcRn)), NameSet)
forall (body :: * -> *).
AnnoBody body =>
HsMatchContextRn
-> (LocatedA (body GhcPs) -> RnM (LocatedA (body GhcRn), NameSet))
-> GRHSs GhcPs (LocatedA (body GhcPs))
-> RnM (GRHSs GhcRn (LocatedA (body GhcRn)), NameSet)
rnGRHSs HsMatchContextRn
ctxt LocatedA (body GhcPs) -> RnM (LocatedA (body GhcRn), NameSet)
rnBody GRHSs GhcPs (LocatedA (body GhcPs))
grhss
        ; let mf' = case (HsMatchContextRn
HsMatchContext (GenLocated SrcSpanAnnN Name)
ctxt, HsMatchContext (LIdP (NoGhcTc GhcPs))
HsMatchContext (LocatedN RdrName)
mf) of
                      (FunRhs { mc_fun :: forall fn. HsMatchContext fn -> fn
mc_fun = L SrcSpanAnnN
_ Name
funid }, FunRhs { mc_fun :: forall fn. HsMatchContext fn -> fn
mc_fun = L SrcSpanAnnN
lf RdrName
_ })
                                            -> HsMatchContext (LIdP (NoGhcTc GhcPs))
mf { mc_fun = L lf funid }
                      (HsMatchContext (GenLocated SrcSpanAnnN Name),
 HsMatchContext (LocatedN RdrName))
_                     -> HsMatchContextRn
HsMatchContext (GenLocated SrcSpanAnnN Name)
ctxt
        ; return (Match { m_ext = noExtField, m_ctxt = mf', m_pats = L l pats'
                        , m_grhss = grhss'}, grhss_fvs ) }


{-
************************************************************************
*                                                                      *
\subsubsection{Guarded right-hand sides (GRHSs)}
*                                                                      *
************************************************************************
-}

rnGRHSs :: AnnoBody body
        => HsMatchContextRn
        -> (LocatedA (body GhcPs) -> RnM (LocatedA (body GhcRn), FreeVars))
        -> GRHSs GhcPs (LocatedA (body GhcPs))
        -> RnM (GRHSs GhcRn (LocatedA (body GhcRn)), FreeVars)
rnGRHSs :: forall (body :: * -> *).
AnnoBody body =>
HsMatchContextRn
-> (LocatedA (body GhcPs) -> RnM (LocatedA (body GhcRn), NameSet))
-> GRHSs GhcPs (LocatedA (body GhcPs))
-> RnM (GRHSs GhcRn (LocatedA (body GhcRn)), NameSet)
rnGRHSs HsMatchContextRn
ctxt LocatedA (body GhcPs) -> RnM (LocatedA (body GhcRn), NameSet)
rnBody (GRHSs XCGRHSs GhcPs (LocatedA (body GhcPs))
_ [LGRHS GhcPs (LocatedA (body GhcPs))]
grhss HsLocalBinds GhcPs
binds)
  = HsLocalBinds GhcPs
-> (HsLocalBinds GhcRn
    -> NameSet -> RnM (GRHSs GhcRn (LocatedA (body GhcRn)), NameSet))
-> RnM (GRHSs GhcRn (LocatedA (body GhcRn)), NameSet)
forall result.
HsLocalBinds GhcPs
-> (HsLocalBinds GhcRn -> NameSet -> RnM (result, NameSet))
-> RnM (result, NameSet)
rnLocalBindsAndThen HsLocalBinds GhcPs
binds   ((HsLocalBinds GhcRn
  -> NameSet -> RnM (GRHSs GhcRn (LocatedA (body GhcRn)), NameSet))
 -> RnM (GRHSs GhcRn (LocatedA (body GhcRn)), NameSet))
-> (HsLocalBinds GhcRn
    -> NameSet -> RnM (GRHSs GhcRn (LocatedA (body GhcRn)), NameSet))
-> RnM (GRHSs GhcRn (LocatedA (body GhcRn)), NameSet)
forall a b. (a -> b) -> a -> b
$ \ HsLocalBinds GhcRn
binds' NameSet
_ -> do
    (grhss', fvGRHSs) <- (GenLocated EpAnnCO (GRHS GhcPs (LocatedA (body GhcPs)))
 -> RnM
      (GenLocated EpAnnCO (GRHS GhcRn (LocatedA (body GhcRn))), NameSet))
-> [GenLocated EpAnnCO (GRHS GhcPs (LocatedA (body GhcPs)))]
-> RnM
     ([GenLocated EpAnnCO (GRHS GhcRn (LocatedA (body GhcRn)))],
      NameSet)
forall (f :: * -> *) a b.
Traversable f =>
(a -> RnM (b, NameSet)) -> f a -> RnM (f b, NameSet)
mapFvRn (HsMatchContextRn
-> (LocatedA (body GhcPs) -> RnM (LocatedA (body GhcRn), NameSet))
-> LGRHS GhcPs (LocatedA (body GhcPs))
-> RnM (LGRHS GhcRn (LocatedA (body GhcRn)), NameSet)
forall (body :: * -> *).
AnnoBody body =>
HsMatchContextRn
-> (LocatedA (body GhcPs) -> RnM (LocatedA (body GhcRn), NameSet))
-> LGRHS GhcPs (LocatedA (body GhcPs))
-> RnM (LGRHS GhcRn (LocatedA (body GhcRn)), NameSet)
rnGRHS HsMatchContextRn
ctxt LocatedA (body GhcPs) -> RnM (LocatedA (body GhcRn), NameSet)
rnBody) [LGRHS GhcPs (LocatedA (body GhcPs))]
[GenLocated EpAnnCO (GRHS GhcPs (LocatedA (body GhcPs)))]
grhss
    return (GRHSs emptyComments grhss' binds', fvGRHSs)

rnGRHS :: AnnoBody body
       => HsMatchContextRn
       -> (LocatedA (body GhcPs) -> RnM (LocatedA (body GhcRn), FreeVars))
       -> LGRHS GhcPs (LocatedA (body GhcPs))
       -> RnM (LGRHS GhcRn (LocatedA (body GhcRn)), FreeVars)
rnGRHS :: forall (body :: * -> *).
AnnoBody body =>
HsMatchContextRn
-> (LocatedA (body GhcPs) -> RnM (LocatedA (body GhcRn), NameSet))
-> LGRHS GhcPs (LocatedA (body GhcPs))
-> RnM (LGRHS GhcRn (LocatedA (body GhcRn)), NameSet)
rnGRHS HsMatchContextRn
ctxt LocatedA (body GhcPs) -> RnM (LocatedA (body GhcRn), NameSet)
rnBody = (GRHS GhcPs (LocatedA (body GhcPs))
 -> TcM (GRHS GhcRn (LocatedA (body GhcRn)), NameSet))
-> GenLocated EpAnnCO (GRHS GhcPs (LocatedA (body GhcPs)))
-> TcM
     (GenLocated EpAnnCO (GRHS GhcRn (LocatedA (body GhcRn))), NameSet)
forall a b c ann.
(a -> TcM (b, c))
-> GenLocated (EpAnn ann) a -> TcM (GenLocated (EpAnn ann) b, c)
wrapLocFstMA (HsMatchContextRn
-> (LocatedA (body GhcPs) -> RnM (LocatedA (body GhcRn), NameSet))
-> GRHS GhcPs (LocatedA (body GhcPs))
-> TcM (GRHS GhcRn (LocatedA (body GhcRn)), NameSet)
forall (body :: * -> *).
HsMatchContextRn
-> (LocatedA (body GhcPs) -> RnM (LocatedA (body GhcRn), NameSet))
-> GRHS GhcPs (LocatedA (body GhcPs))
-> RnM (GRHS GhcRn (LocatedA (body GhcRn)), NameSet)
rnGRHS' HsMatchContextRn
ctxt LocatedA (body GhcPs) -> RnM (LocatedA (body GhcRn), NameSet)
rnBody)

rnGRHS' :: HsMatchContextRn
        -> (LocatedA (body GhcPs) -> RnM (LocatedA (body GhcRn), FreeVars))
        -> GRHS GhcPs (LocatedA (body GhcPs))
        -> RnM (GRHS GhcRn (LocatedA (body GhcRn)), FreeVars)
rnGRHS' :: forall (body :: * -> *).
HsMatchContextRn
-> (LocatedA (body GhcPs) -> RnM (LocatedA (body GhcRn), NameSet))
-> GRHS GhcPs (LocatedA (body GhcPs))
-> RnM (GRHS GhcRn (LocatedA (body GhcRn)), NameSet)
rnGRHS' HsMatchContextRn
ctxt LocatedA (body GhcPs) -> RnM (LocatedA (body GhcRn), NameSet)
rnBody (GRHS XCGRHS GhcPs (LocatedA (body GhcPs))
_ [GuardLStmt GhcPs]
guards LocatedA (body GhcPs)
rhs)
  = do  { pattern_guards_allowed <- Extension -> TcRnIf TcGblEnv TcLclEnv Bool
forall gbl lcl. Extension -> TcRnIf gbl lcl Bool
xoptM Extension
LangExt.PatternGuards
        ; ((guards', rhs'), fvs) <- rnStmts (PatGuard ctxt) rnExpr guards $ \ [Name]
_ ->
                                    LocatedA (body GhcPs) -> RnM (LocatedA (body GhcRn), NameSet)
rnBody LocatedA (body GhcPs)
rhs

        ; unless (pattern_guards_allowed || is_standard_guard guards') $
            addDiagnostic (nonStdGuardErr guards')

        ; return (GRHS noAnn guards' rhs', fvs) }
  where
        -- Standard Haskell 1.4 guards are just a single boolean
        -- expression, rather than a list of qualifiers as in the
        -- Glasgow extension
    is_standard_guard :: [GenLocated l (StmtLR idL idR body)] -> Bool
is_standard_guard []                  = Bool
True
    is_standard_guard [L l
_ (BodyStmt {})] = Bool
True
    is_standard_guard [GenLocated l (StmtLR idL idR body)]
_                   = Bool
False

{-
*********************************************************
*                                                       *
        Source-code fixity declarations
*                                                       *
*********************************************************
-}

rnSrcFixityDecl :: HsSigCtxt -> FixitySig GhcPs -> RnM (FixitySig GhcRn)
-- Rename a fixity decl, so we can put
-- the renamed decl in the renamed syntax tree
-- Errors if the thing being fixed is not defined locally.
rnSrcFixityDecl :: HsSigCtxt -> FixitySig GhcPs -> RnM (FixitySig GhcRn)
rnSrcFixityDecl HsSigCtxt
sig_ctxt = FixitySig GhcPs -> RnM (FixitySig GhcRn)
rn_decl
  where
    rn_decl :: FixitySig GhcPs -> RnM (FixitySig GhcRn)
        -- GHC extension: look up both the tycon and data con
        -- for con-like things; hence returning a list
        -- If neither are in scope, report an error; otherwise
        -- return a fixity sig for each (slightly odd)
    rn_decl :: FixitySig GhcPs -> RnM (FixitySig GhcRn)
rn_decl sig :: FixitySig GhcPs
sig@(FixitySig XFixitySig GhcPs
ns_spec [LIdP GhcPs]
fnames Fixity
fixity)
      = do Extension -> TcM () -> TcM ()
forall gbl lcl. Extension -> TcRnIf gbl lcl () -> TcRnIf gbl lcl ()
unlessXOptM Extension
LangExt.ExplicitNamespaces (TcM () -> TcM ()) -> TcM () -> TcM ()
forall a b. (a -> b) -> a -> b
$
             Bool -> TcM () -> TcM ()
forall (f :: * -> *). Applicative f => Bool -> f () -> f ()
when (XFixitySig GhcPs
NamespaceSpecifier
ns_spec NamespaceSpecifier -> NamespaceSpecifier -> Bool
forall a. Eq a => a -> a -> Bool
/= NamespaceSpecifier
NoNamespaceSpecifier) (TcM () -> TcM ()) -> TcM () -> TcM ()
forall a b. (a -> b) -> a -> b
$
             TcRnMessage -> TcM ()
addErr (FixitySig GhcPs -> TcRnMessage
TcRnNamespacedFixitySigWithoutFlag FixitySig GhcPs
sig)
           names <- (LocatedN RdrName
 -> IOEnv (Env TcGblEnv TcLclEnv) [GenLocated SrcSpanAnnN Name])
-> [LocatedN RdrName]
-> IOEnv (Env TcGblEnv TcLclEnv) [GenLocated SrcSpanAnnN Name]
forall (m :: * -> *) (f :: * -> *) a b.
(Monad m, Traversable f) =>
(a -> m [b]) -> f a -> m [b]
concatMapM (NamespaceSpecifier
-> LocatedN RdrName
-> IOEnv (Env TcGblEnv TcLclEnv) [GenLocated SrcSpanAnnN Name]
lookup_one XFixitySig GhcPs
NamespaceSpecifier
ns_spec) [LIdP GhcPs]
[LocatedN RdrName]
fnames
           return (FixitySig ns_spec names fixity)

    lookup_one :: NamespaceSpecifier -> LocatedN RdrName -> RnM [LocatedN Name]
    lookup_one :: NamespaceSpecifier
-> LocatedN RdrName
-> IOEnv (Env TcGblEnv TcLclEnv) [GenLocated SrcSpanAnnN Name]
lookup_one NamespaceSpecifier
ns_spec (L SrcSpanAnnN
name_loc RdrName
rdr_name)
      = SrcSpanAnnN
-> IOEnv (Env TcGblEnv TcLclEnv) [GenLocated SrcSpanAnnN Name]
-> IOEnv (Env TcGblEnv TcLclEnv) [GenLocated SrcSpanAnnN Name]
forall ann a. EpAnn ann -> TcRn a -> TcRn a
setSrcSpanA SrcSpanAnnN
name_loc (IOEnv (Env TcGblEnv TcLclEnv) [GenLocated SrcSpanAnnN Name]
 -> IOEnv (Env TcGblEnv TcLclEnv) [GenLocated SrcSpanAnnN Name])
-> IOEnv (Env TcGblEnv TcLclEnv) [GenLocated SrcSpanAnnN Name]
-> IOEnv (Env TcGblEnv TcLclEnv) [GenLocated SrcSpanAnnN Name]
forall a b. (a -> b) -> a -> b
$
                    -- This lookup will fail if the name is not defined in the
                    -- same binding group as this fixity declaration.
        do names <- HsSigCtxt
-> SDoc -> NamespaceSpecifier -> RdrName -> RnM [(RdrName, Name)]
lookupLocalTcNames HsSigCtxt
sig_ctxt SDoc
what NamespaceSpecifier
ns_spec RdrName
rdr_name
           return [ L name_loc name | (_, name) <- names ]
    what :: SDoc
what = String -> SDoc
forall doc. IsLine doc => String -> doc
text String
"fixity signature"

{-
************************************************************************
*                                                                      *
\subsection{Error messages}
*                                                                      *
************************************************************************
-}

dupSigDeclErr :: NonEmpty (LocatedN RdrName, Sig GhcPs) -> RnM ()
dupSigDeclErr :: NonEmpty (LocatedN RdrName, Sig GhcPs) -> TcM ()
dupSigDeclErr pairs :: NonEmpty (LocatedN RdrName, Sig GhcPs)
pairs@((L SrcSpanAnnN
loc RdrName
_, Sig GhcPs
_) :| [(LocatedN RdrName, Sig GhcPs)]
_)
  = SrcSpan -> TcRnMessage -> TcM ()
addErrAt (SrcSpanAnnN -> SrcSpan
forall a. HasLoc a => a -> SrcSpan
locA SrcSpanAnnN
loc) (TcRnMessage -> TcM ()) -> TcRnMessage -> TcM ()
forall a b. (a -> b) -> a -> b
$ NonEmpty (LocatedN RdrName, Sig GhcPs) -> TcRnMessage
TcRnDuplicateSigDecl NonEmpty (LocatedN RdrName, Sig GhcPs)
pairs

misplacedSigErr :: LSig GhcRn -> RnM ()
misplacedSigErr :: LSig GhcRn -> TcM ()
misplacedSigErr (L SrcSpanAnnA
loc Sig GhcRn
sig)
  = SrcSpan -> TcRnMessage -> TcM ()
addErrAt (SrcSpanAnnA -> SrcSpan
forall a. HasLoc a => a -> SrcSpan
locA SrcSpanAnnA
loc) (TcRnMessage -> TcM ()) -> TcRnMessage -> TcM ()
forall a b. (a -> b) -> a -> b
$ Sig GhcRn -> TcRnMessage
TcRnMisplacedSigDecl Sig GhcRn
sig

nonStdGuardErr :: (Outputable body,
                   Anno (Stmt GhcRn body) ~ SrcSpanAnnA)
               => [LStmtLR GhcRn GhcRn body] -> TcRnMessage
nonStdGuardErr :: forall body.
(Outputable body, Anno (Stmt GhcRn body) ~ SrcSpanAnnA) =>
[LStmtLR GhcRn GhcRn body] -> TcRnMessage
nonStdGuardErr [LStmtLR GhcRn GhcRn body]
guards = NonStandardGuards -> TcRnMessage
TcRnNonStdGuards ([LStmtLR GhcRn GhcRn body] -> NonStandardGuards
forall body.
(Outputable body, Anno (Stmt GhcRn body) ~ SrcSpanAnnA) =>
[LStmtLR GhcRn GhcRn body] -> NonStandardGuards
NonStandardGuards [LStmtLR GhcRn GhcRn body]
guards)

dupMinimalSigErr :: LSig GhcPs -> LSig GhcPs -> [LSig GhcPs] -> RnM ()
dupMinimalSigErr :: XRec GhcPs (Sig GhcPs)
-> XRec GhcPs (Sig GhcPs) -> [XRec GhcPs (Sig GhcPs)] -> TcM ()
dupMinimalSigErr XRec GhcPs (Sig GhcPs)
sig1 XRec GhcPs (Sig GhcPs)
sig2 [XRec GhcPs (Sig GhcPs)]
otherSigs
  = SrcSpan -> TcRnMessage -> TcM ()
addErrAt (GenLocated SrcSpanAnnA (Sig GhcPs) -> SrcSpan
forall a e. HasLoc a => GenLocated a e -> SrcSpan
getLocA XRec GhcPs (Sig GhcPs)
GenLocated SrcSpanAnnA (Sig GhcPs)
sig1) (TcRnMessage -> TcM ()) -> TcRnMessage -> TcM ()
forall a b. (a -> b) -> a -> b
$ XRec GhcPs (Sig GhcPs)
-> XRec GhcPs (Sig GhcPs)
-> [XRec GhcPs (Sig GhcPs)]
-> TcRnMessage
TcRnDuplicateMinimalSig XRec GhcPs (Sig GhcPs)
sig1 XRec GhcPs (Sig GhcPs)
sig2 [XRec GhcPs (Sig GhcPs)]
otherSigs