%
-% (c) The GRASP/AQUA Project, Glasgow University, 1993-1995
+% (c) The GRASP/AQUA Project, Glasgow University, 1993-1998
%
\section[CoreLint]{A ``lint'' pass to check for Core correctness}
\begin{code}
-#include "HsVersions.h"
-
module CoreLint (
lintCoreBindings,
- lintUnfolding,
-
- PprStyle, CoreBinding, PlainCoreBinding(..), Id
+ lintUnfolding,
+ showPass, endPass
) where
-IMPORT_Trace
+#include "HsVersions.h"
-import AbsPrel ( typeOfPrimOp, mkFunTy, PrimOp(..), PrimKind
- IF_ATTACK_PRAGMAS(COMMA tagOf_PrimOp)
- IF_ATTACK_PRAGMAS(COMMA pprPrimOp)
- )
-import AbsUniType
+import CoreSyn
+import CoreFVs ( idFreeVars )
+import CoreUtils ( findDefault, exprOkForSpeculation, coreBindsSize )
+import Unify ( coreRefineTys )
import Bag
-import BasicLit ( typeOfBasicLit, BasicLit )
-import CoreSyn ( pprCoreBinding ) -- ToDo: correctly
-import Id ( getIdUniType, isNullaryDataCon, isBottomingId,
- getInstantiatedDataConSig, Id
- IF_ATTACK_PRAGMAS(COMMA bottomIsGuaranteed)
- )
-import Maybes
+import Literal ( literalType )
+import DataCon ( dataConRepType, isVanillaDataCon, dataConTyCon, dataConWorkId )
+import TysWiredIn ( tupleCon )
+import Var ( Var, Id, TyVar, idType, tyVarKind, mustHaveLocalBinding )
+import VarSet
+import Name ( getSrcLoc )
+import PprCore
+import ErrUtils ( dumpIfSet_core, ghcExit, Message, showPass,
+ mkLocMessage, debugTraceMsg )
+import SrcLoc ( SrcLoc, noSrcLoc, mkSrcSpan )
+import Type ( Type, tyVarsOfType, coreEqType,
+ splitFunTy_maybe, mkTyVarTys,
+ splitForAllTy_maybe, splitTyConApp_maybe,
+ isUnLiftedType, typeKind, mkForAllTy, mkFunTy,
+ isUnboxedTupleType, isSubKind,
+ substTyWith, emptyTvSubst, extendTvInScope,
+ TvSubst, TvSubstEnv, mkTvSubst, setTvSubstEnv, substTy,
+ extendTvSubst, composeTvSubst, isInScope,
+ getTvSubstEnv, getTvInScope )
+import TyCon ( isPrimTyCon )
+import BasicTypes ( RecFlag(..), Boxity(..), isNonRec )
+import StaticFlags ( opt_PprStyle_Debug )
+import DynFlags ( DynFlags, DynFlag(..), dopt )
import Outputable
-import PlainCore
-import Pretty
-import SrcLoc ( SrcLoc )
-import UniqSet
-import Util
-infixr 9 `thenL`, `thenL_`, `thenMaybeL`, `thenMaybeL_`
+#ifdef DEBUG
+import Util ( notNull )
+#endif
+
+import Maybe
+
\end{code}
-Checks for
- (a) type errors
- (b) locally-defined variables used but not defined
+%************************************************************************
+%* *
+\subsection{End pass}
+%* *
+%************************************************************************
+
+@showPass@ and @endPass@ don't really belong here, but it makes a convenient
+place for them. They print out stuff before and after core passes,
+and do Core Lint when necessary.
+
+\begin{code}
+endPass :: DynFlags -> String -> DynFlag -> [CoreBind] -> IO [CoreBind]
+endPass dflags pass_name dump_flag binds
+ = do
+ -- Report result size if required
+ -- This has the side effect of forcing the intermediate to be evaluated
+ debugTraceMsg dflags 2 $
+ (text " Result size =" <+> int (coreBindsSize binds))
+
+ -- Report verbosely, if required
+ dumpIfSet_core dflags dump_flag pass_name (pprCoreBindings binds)
+
+ -- Type check
+ lintCoreBindings dflags pass_name binds
+
+ return binds
+\end{code}
-Doesn't check for out-of-scope type variables, because they can
-legitimately arise. Eg
-\begin{verbatim}
- k = /\a b -> \x::a y::b -> x
- f = /\c -> \z::c -> k c w z (error w "foo")
-\end{verbatim}
-Here \tr{w} is just a free type variable.
%************************************************************************
%* *
-\subsection{``lint'' for various constructs}
+\subsection[lintCoreBindings]{@lintCoreBindings@: Top-level interface}
%* *
%************************************************************************
-@lintCoreBindings@ is the top-level interface function.
+Checks that a set of core bindings is well-formed. The PprStyle and String
+just control what we print in the event of an error. The Bool value
+indicates whether we have done any specialisation yet (in which case we do
+some extra checks).
+
+We check for
+ (a) type errors
+ (b) Out-of-scope type variables
+ (c) Out-of-scope local variables
+ (d) Ill-kinded types
+
+If we have done specialisation the we check that there are
+ (a) No top-level bindings of primitive (unboxed type)
+
+Outstanding issues:
+
+ --
+ -- Things are *not* OK if:
+ --
+ -- * Unsaturated type app before specialisation has been done;
+ --
+ -- * Oversaturated type app after specialisation (eta reduction
+ -- may well be happening...);
\begin{code}
-lintCoreBindings :: PprStyle -> String -> Bool -> [PlainCoreBinding] -> [PlainCoreBinding]
-
-lintCoreBindings sty whodunnit spec_done binds
- = BSCC("CoreLint")
- case (initL (lint_binds binds) spec_done) of
- Nothing -> binds
- Just msg -> pprPanic "" (ppAboves [
- ppStr ("*** Core Lint Errors: in "++whodunnit++" ***"),
- msg sty,
- ppStr "*** Offending Program ***",
- ppAboves (map (pprCoreBinding sty pprBigCoreBinder pprTypedCoreBinder ppr) binds),
- ppStr "*** End of Offense ***"])
- ESCC
+lintCoreBindings :: DynFlags -> String -> [CoreBind] -> IO ()
+
+lintCoreBindings dflags whoDunnit binds
+ | not (dopt Opt_DoCoreLinting dflags)
+ = return ()
+
+lintCoreBindings dflags whoDunnit binds
+ = case (initL (lint_binds binds)) of
+ Nothing -> showPass dflags ("Core Linted result of " ++ whoDunnit)
+ Just bad_news -> printDump (display bad_news) >>
+ ghcExit dflags 1
where
- lint_binds :: [PlainCoreBinding] -> LintM ()
-
- lint_binds [] = returnL ()
- lint_binds (bind:binds)
- = lintCoreBinds bind `thenL` \ binders ->
- addInScopeVars binders (
- lint_binds binds
- )
+ -- Put all the top-level binders in scope at the start
+ -- This is because transformation rules can bring something
+ -- into use 'unexpectedly'
+ lint_binds binds = addInScopeVars (bindersOfBinds binds) $
+ mapM lint_bind binds
+
+ lint_bind (Rec prs) = mapM_ (lintSingleBinding Recursive) prs
+ lint_bind (NonRec bndr rhs) = lintSingleBinding NonRecursive (bndr,rhs)
+
+ display bad_news
+ = vcat [ text ("*** Core Lint Errors: in result of " ++ whoDunnit ++ " ***"),
+ bad_news,
+ ptext SLIT("*** Offending Program ***"),
+ pprCoreBindings binds,
+ ptext SLIT("*** End of Offense ***")
+ ]
\end{code}
+%************************************************************************
+%* *
+\subsection[lintUnfolding]{lintUnfolding}
+%* *
+%************************************************************************
+
We use this to check all unfoldings that come in from interfaces
(it is very painful to catch errors otherwise):
+
\begin{code}
-lintUnfolding :: SrcLoc -> PlainCoreExpr -> PlainCoreExpr
-
-lintUnfolding locn expr
- = case (initL (addLoc (ImportedUnfolding locn) (lintCoreExpr expr)) True{-pretend spec done-}) of
- Nothing -> expr
- Just msg -> error ("ERROR: Type-incorrect unfolding from an interface:\n"++
- (ppShow 80 (ppAboves [msg PprForUser,
- ppStr "*** Bad unfolding ***",
- ppr PprDebug expr,
- ppStr "*** End of bad unfolding ***"])))
+lintUnfolding :: SrcLoc
+ -> [Var] -- Treat these as in scope
+ -> CoreExpr
+ -> Maybe Message -- Nothing => OK
+
+lintUnfolding locn vars expr
+ = initL (addLoc (ImportedUnfolding locn) $
+ addInScopeVars vars $
+ lintCoreExpr expr)
\end{code}
-\begin{code}
-lintCoreAtom :: PlainCoreAtom -> LintM (Maybe UniType)
+%************************************************************************
+%* *
+\subsection[lintCoreBinding]{lintCoreBinding}
+%* *
+%************************************************************************
-lintCoreAtom (CoLitAtom lit) = returnL (Just (typeOfBasicLit lit))
-lintCoreAtom a@(CoVarAtom v)
- = checkInScope v `thenL_`
- returnL (Just (getIdUniType v))
-\end{code}
+Check a core binding, returning the list of variables bound.
\begin{code}
-lintCoreBinds :: PlainCoreBinding -> LintM [Id] -- Returns the binders
-lintCoreBinds (CoNonRec binder rhs)
- = lint_binds_help (binder,rhs) `thenL_`
- returnL [binder]
-
-lintCoreBinds (CoRec pairs)
- = addInScopeVars binders (
- mapL lint_binds_help pairs `thenL_`
- returnL binders
- )
+lintSingleBinding rec_flag (binder,rhs)
+ = addLoc (RhsOf binder) $
+ -- Check the rhs
+ do { ty <- lintCoreExpr rhs
+ ; lintBinder binder -- Check match to RHS type
+ ; binder_ty <- applySubst binder_ty
+ ; checkTys binder_ty ty (mkRhsMsg binder ty)
+ -- Check (not isUnLiftedType) (also checks for bogus unboxed tuples)
+ ; checkL (not (isUnLiftedType binder_ty)
+ || (isNonRec rec_flag && exprOkForSpeculation rhs))
+ (mkRhsPrimMsg binder rhs)
+ -- Check whether binder's specialisations contain any out-of-scope variables
+ ; mapM_ (checkBndrIdInScope binder) bndr_vars }
+
+ -- We should check the unfolding, if any, but this is tricky because
+ -- the unfolding is a SimplifiableCoreExpr. Give up for now.
where
- binders = [b | (b,_) <- pairs]
-
-lint_binds_help (binder,rhs)
- = addLoc (RhsOf binder) (
- -- Check the rhs
- lintCoreExpr rhs `thenL` \ maybe_rhs_ty ->
-
- -- Check match to RHS type
- (case maybe_rhs_ty of
- Nothing -> returnL ()
- Just rhs_ty -> checkTys (getIdUniType binder)
- rhs_ty
- (mkRhsMsg binder rhs_ty)
- ) `thenL_`
-
- -- Check not isPrimType
- checkL (not (isPrimType (getIdUniType binder)))
- (mkRhsPrimMsg binder rhs)
- `thenL_`
-
- -- Check unfolding, if any
- -- Blegh. This is tricky, because the unfolding is a SimplifiableCoreExpr
- -- Give up for now
-
- returnL ()
- )
+ binder_ty = idType binder
+ bndr_vars = varSetElems (idFreeVars binder)
\end{code}
+%************************************************************************
+%* *
+\subsection[lintCoreExpr]{lintCoreExpr}
+%* *
+%************************************************************************
+
\begin{code}
-lintCoreExpr :: PlainCoreExpr -> LintM (Maybe UniType) -- Nothing if error found
-
-lintCoreExpr (CoVar var)
- = checkInScope var `thenL_`
- returnL (Just ty)
-{-
- case (splitForalls ty) of { (tyvars, _) ->
- if null tyvars then
- returnL (Just ty)
- else
- addErrL (mkUnappTyMsg var ty) `thenL_`
- returnL Nothing
- }
--}
- where
- ty = getIdUniType var
-
-lintCoreExpr (CoLit lit) = returnL (Just (typeOfBasicLit lit))
-lintCoreExpr (CoSCC label expr) = lintCoreExpr expr
-
-lintCoreExpr (CoLet binds body)
- = lintCoreBinds binds `thenL` \ binders ->
- ASSERT(not (null binders))
- addLoc (BodyOfLetRec binders) (
- addInScopeVars binders (
- lintCoreExpr body
- ))
-
-lintCoreExpr e@(CoCon con tys args)
- = checkTyApp con_ty tys (mkTyAppMsg e) `thenMaybeL` \ con_tau_ty ->
- -- Note: no call to checkSpecTyApp;
- -- we allow CoCons applied to unboxed types to sail through
- mapMaybeL lintCoreAtom args `thenL` \ maybe_arg_tys ->
- case maybe_arg_tys of
- Nothing -> returnL Nothing
- Just arg_tys -> checkFunApp con_tau_ty arg_tys (mkFunAppMsg con_tau_ty arg_tys e)
+type InType = Type -- Substitution not yet applied
+type OutType = Type -- Substitution has been applied to this
+
+lintCoreExpr :: CoreExpr -> LintM OutType
+-- The returned type has the substitution from the monad
+-- already applied to it:
+-- lintCoreExpr e subst = exprType (subst e)
+
+lintCoreExpr (Var var)
+ = do { checkIdInScope var
+ ; applySubst (idType var) }
+
+lintCoreExpr (Lit lit)
+ = return (literalType lit)
+
+lintCoreExpr (Note (Coerce to_ty from_ty) expr)
+ = do { expr_ty <- lintCoreExpr expr
+ ; to_ty <- lintTy to_ty
+ ; from_ty <- lintTy from_ty
+ ; checkTys from_ty expr_ty (mkCoerceErr from_ty expr_ty)
+ ; return to_ty }
+
+lintCoreExpr (Note other_note expr)
+ = lintCoreExpr expr
+
+lintCoreExpr (Let (NonRec bndr rhs) body)
+ = do { lintSingleBinding NonRecursive (bndr,rhs)
+ ; addLoc (BodyOfLetRec [bndr])
+ (addInScopeVars [bndr] (lintCoreExpr body)) }
+
+lintCoreExpr (Let (Rec pairs) body)
+ = addInScopeVars bndrs $
+ do { mapM (lintSingleBinding Recursive) pairs
+ ; addLoc (BodyOfLetRec bndrs) (lintCoreExpr body) }
where
- con_ty = getIdUniType con
-
-lintCoreExpr e@(CoPrim op tys args)
- = checkTyApp op_ty tys (mkTyAppMsg e) `thenMaybeL` \ op_tau_ty ->
- -- checkSpecTyApp e tys (mkSpecTyAppMsg e) `thenMaybeL_`
- mapMaybeL lintCoreAtom args `thenL` \ maybe_arg_tys ->
- case maybe_arg_tys of
- Nothing -> returnL Nothing
- Just arg_tys -> checkFunApp op_tau_ty arg_tys (mkFunAppMsg op_tau_ty arg_tys e)
+ bndrs = map fst pairs
+
+lintCoreExpr e@(App fun (Type ty))
+-- This is like 'let' for types
+-- It's needed when dealing with desugarer output for GADTs. Consider
+-- data T = forall a. T a (a->Int) Bool
+-- f :: T -> ... ->
+-- f (T x f True) = <e1>
+-- f (T y g False) = <e2>
+-- After desugaring we get
+-- f t b = case t of
+-- T a (x::a) (f::a->Int) (b:Bool) ->
+-- case b of
+-- True -> <e1>
+-- False -> (/\b. let y=x; g=f in <e2>) a
+-- And for a reason I now forget, the ...<e2>... can mention a; so
+-- we want Lint to know that b=a. Ugh.
+--
+-- I tried quite hard to make the necessity for this go away, by changing the
+-- desugarer, but the fundamental problem is this:
+--
+-- T a (x::a) (y::Int) -> let fail::a = ...
+-- in (/\b. ...(case ... of
+-- True -> x::b
+-- False -> fail)
+-- ) a
+-- Now the inner case look as though it has incompatible branches.
+ = addLoc (AnExpr e) $
+ go fun [ty]
where
- op_ty = typeOfPrimOp op
+ go (App fun (Type ty)) tys
+ = do { go fun (ty:tys) }
+ go (Lam tv body) (ty:tys)
+ = do { checkL (isTyVar tv) (mkKindErrMsg tv ty) -- Not quite accurate
+ ; ty' <- lintTy ty;
+ ; checkKinds tv ty'
+ -- Now extend the substitution so we
+ -- take advantage of it in the body
+ ; addInScopeVars [tv] $
+ extendSubstL tv ty' $
+ go body tys }
+ go fun tys
+ = do { fun_ty <- lintCoreExpr fun
+ ; lintCoreArgs fun_ty (map Type tys) }
+
+lintCoreExpr e@(App fun arg)
+ = do { fun_ty <- lintCoreExpr fun
+ ; addLoc (AnExpr e) $
+ lintCoreArg fun_ty arg }
+
+lintCoreExpr (Lam var expr)
+ = addLoc (LambdaBodyOf var) $
+ do { body_ty <- addInScopeVars [var] $
+ lintCoreExpr expr
+ ; if isId var then do
+ { var_ty <- lintId var
+ ; return (mkFunTy var_ty body_ty) }
+ else
+ return (mkForAllTy var body_ty)
+ }
+ -- The applySubst is needed to apply the subst to var
+
+lintCoreExpr e@(Case scrut var alt_ty alts) =
+ -- Check the scrutinee
+ do { scrut_ty <- lintCoreExpr scrut
+ ; alt_ty <- lintTy alt_ty
+ ; var_ty <- lintTy (idType var)
+ -- Don't use lintId on var, because unboxed tuple is legitimate
+
+ ; checkTys var_ty scrut_ty (mkScrutMsg var scrut_ty)
+
+ -- If the binder is an unboxed tuple type, don't put it in scope
+ ; let vars = if (isUnboxedTupleType (idType var)) then [] else [var]
+ ; addInScopeVars vars $
+ do { -- Check the alternatives
+ checkCaseAlts e scrut_ty alts
+ ; mapM (lintCoreAlt scrut_ty alt_ty) alts
+ ; return alt_ty } }
+
+lintCoreExpr e@(Type ty)
+ = addErrL (mkStrangeTyMsg e)
+\end{code}
-lintCoreExpr e@(CoApp fun arg)
- = lce e []
- where
- lce (CoApp fun arg) arg_tys = lintCoreAtom arg `thenMaybeL` \ arg_ty ->
- lce fun (arg_ty:arg_tys)
+%************************************************************************
+%* *
+\subsection[lintCoreArgs]{lintCoreArgs}
+%* *
+%************************************************************************
- lce other_fun arg_tys = lintCoreExpr other_fun `thenMaybeL` \ fun_ty ->
- checkFunApp fun_ty arg_tys (mkFunAppMsg fun_ty arg_tys e)
+The basic version of these functions checks that the argument is a
+subtype of the required type, as one would expect.
-lintCoreExpr e@(CoTyApp fun ty_arg)
- = lce e []
+\begin{code}
+lintCoreArgs :: Type -> [CoreArg] -> LintM Type
+lintCoreArg :: Type -> CoreArg -> LintM Type
+-- First argument has already had substitution applied to it
+\end{code}
+
+\begin{code}
+lintCoreArgs ty [] = return ty
+lintCoreArgs ty (a : args) =
+ do { res <- lintCoreArg ty a
+ ; lintCoreArgs res args }
+
+lintCoreArg fun_ty a@(Type arg_ty) =
+ do { arg_ty <- lintTy arg_ty
+ ; lintTyApp fun_ty arg_ty }
+
+lintCoreArg fun_ty arg =
+ -- Make sure function type matches argument
+ do { arg_ty <- lintCoreExpr arg
+ ; let err = mkAppMsg fun_ty arg_ty arg
+ ; case splitFunTy_maybe fun_ty of
+ Just (arg,res) ->
+ do { checkTys arg arg_ty err
+ ; return res }
+ _ -> addErrL err }
+\end{code}
+
+\begin{code}
+-- Both args have had substitution applied
+lintTyApp ty arg_ty
+ = case splitForAllTy_maybe ty of
+ Nothing -> addErrL (mkTyAppMsg ty arg_ty)
+
+ Just (tyvar,body)
+ -> do { checkL (isTyVar tyvar) (mkTyAppMsg ty arg_ty)
+ ; checkKinds tyvar arg_ty
+ ; return (substTyWith [tyvar] [arg_ty] body) }
+
+lintTyApps fun_ty [] = return fun_ty
+
+lintTyApps fun_ty (arg_ty : arg_tys) =
+ do { fun_ty' <- lintTyApp fun_ty arg_ty
+ ; lintTyApps fun_ty' arg_tys }
+
+checkKinds tyvar arg_ty
+ -- Arg type might be boxed for a function with an uncommitted
+ -- tyvar; notably this is used so that we can give
+ -- error :: forall a:*. String -> a
+ -- and then apply it to both boxed and unboxed types.
+ = checkL (argty_kind `isSubKind` tyvar_kind)
+ (mkKindErrMsg tyvar arg_ty)
where
- lce (CoTyApp fun ty_arg) ty_args = lce fun (ty_arg:ty_args)
-
- lce other_fun ty_args = lintCoreExpr other_fun `thenMaybeL` \ fun_ty ->
- checkTyApp fun_ty ty_args (mkTyAppMsg e)
- `thenMaybeL` \ res_ty ->
- checkSpecTyApp other_fun ty_args (mkSpecTyAppMsg e)
- `thenMaybeL_`
- returnL (Just res_ty)
-
-lintCoreExpr (CoLam binders expr)
- = ASSERT (not (null binders))
- addLoc (LambdaBodyOf binders) (
- addInScopeVars binders (
- lintCoreExpr expr `thenMaybeL` \ body_ty ->
- returnL (Just (foldr (mkFunTy . getIdUniType) body_ty binders))
- ))
-
-lintCoreExpr (CoTyLam tyvar expr)
- = lintCoreExpr expr `thenMaybeL` \ body_ty ->
- case quantifyTy [tyvar] body_ty of
- (_, ty) -> returnL (Just ty) -- not worried about the TyVarTemplates that come back
-
-lintCoreExpr e@(CoCase scrut alts)
- = lintCoreExpr scrut `thenMaybeL` \ scrut_ty ->
-
- -- Check that it is a data type
- case getUniDataTyCon_maybe scrut_ty of
- Nothing -> addErrL (mkCaseDataConMsg e) `thenL_`
- returnL Nothing
- Just (tycon, _, _)
- -> lintCoreAlts alts scrut_ty tycon
-
-lintCoreAlts :: PlainCoreCaseAlternatives
- -> UniType -- Type of scrutinee
- -> TyCon -- TyCon pinned on the case
- -> LintM (Maybe UniType) -- Type of alternatives
-
-lintCoreAlts alts scrut_ty case_tycon
- = (case alts of
- CoAlgAlts alg_alts deflt ->
- chk_prim_type False case_tycon `thenL_`
- chk_non_abstract_type case_tycon `thenL_`
- mapL (lintAlgAlt scrut_ty) alg_alts `thenL` \ maybe_alt_tys ->
- lintDeflt deflt scrut_ty `thenL` \ maybe_deflt_ty ->
- returnL (maybe_deflt_ty : maybe_alt_tys)
-
- CoPrimAlts prim_alts deflt ->
- chk_prim_type True case_tycon `thenL_`
- mapL (lintPrimAlt scrut_ty) prim_alts `thenL` \ maybe_alt_tys ->
- lintDeflt deflt scrut_ty `thenL` \ maybe_deflt_ty ->
- returnL (maybe_deflt_ty : maybe_alt_tys)
- ) `thenL` \ maybe_result_tys ->
- -- Check the result types
- case catMaybes (maybe_result_tys) of
- [] -> returnL Nothing
-
- (first_ty:tys) -> mapL check tys `thenL_`
- returnL (Just first_ty)
- where
- check ty = checkTys first_ty ty (mkCaseAltMsg alts)
+ tyvar_kind = tyVarKind tyvar
+ argty_kind = typeKind arg_ty
+\end{code}
+
+
+%************************************************************************
+%* *
+\subsection[lintCoreAlts]{lintCoreAlts}
+%* *
+%************************************************************************
+
+\begin{code}
+checkCaseAlts :: CoreExpr -> OutType -> [CoreAlt] -> LintM ()
+-- a) Check that the alts are non-empty
+-- b1) Check that the DEFAULT comes first, if it exists
+-- b2) Check that the others are in increasing order
+-- c) Check that there's a default for infinite types
+-- NB: Algebraic cases are not necessarily exhaustive, because
+-- the simplifer correctly eliminates case that can't
+-- possibly match.
+
+checkCaseAlts e ty []
+ = addErrL (mkNullAltsMsg e)
+
+checkCaseAlts e ty alts =
+ do { checkL (all non_deflt con_alts) (mkNonDefltMsg e)
+ ; checkL (increasing_tag con_alts) (mkNonIncreasingAltsMsg e)
+ ; checkL (isJust maybe_deflt || not is_infinite_ty)
+ (nonExhaustiveAltsMsg e) }
where
- chk_prim_type prim_required tycon
- = if (isPrimTyCon tycon == prim_required) then
- returnL ()
- else
- addErrL (mkCasePrimMsg prim_required tycon)
-
- chk_non_abstract_type tycon
- = case (getTyConFamilySize tycon) of
- Nothing -> addErrL (mkCaseAbstractMsg tycon)
- Just _ -> returnL ()
-
-
-lintAlgAlt scrut_ty (con,args,rhs)
- = (case getUniDataTyCon_maybe scrut_ty of
- Nothing ->
- addErrL (mkAlgAltMsg1 scrut_ty)
- Just (tycon, tys_applied, cons) ->
- let
- (_, arg_tys, _) = getInstantiatedDataConSig con tys_applied
- in
- checkL (con `elem` cons) (mkAlgAltMsg2 scrut_ty con) `thenL_`
- checkL (length arg_tys == length args) (mkAlgAltMsg3 con args)
- `thenL_`
- mapL check (arg_tys `zipEqual` args) `thenL_`
- returnL ()
- ) `thenL_`
- addInScopeVars args (
- lintCoreExpr rhs
- )
+ (con_alts, maybe_deflt) = findDefault alts
+
+ -- Check that successive alternatives have increasing tags
+ increasing_tag (alt1 : rest@( alt2 : _)) = alt1 `ltAlt` alt2 && increasing_tag rest
+ increasing_tag other = True
+
+ non_deflt (DEFAULT, _, _) = False
+ non_deflt alt = True
+
+ is_infinite_ty = case splitTyConApp_maybe ty of
+ Nothing -> False
+ Just (tycon, tycon_arg_tys) -> isPrimTyCon tycon
+\end{code}
+
+\begin{code}
+checkAltExpr :: CoreExpr -> OutType -> LintM ()
+checkAltExpr expr ann_ty
+ = do { actual_ty <- lintCoreExpr expr
+ ; checkTys actual_ty ann_ty (mkCaseAltMsg expr actual_ty ann_ty) }
+
+lintCoreAlt :: OutType -- Type of scrutinee
+ -> OutType -- Type of the alternative
+ -> CoreAlt
+ -> LintM ()
+
+lintCoreAlt scrut_ty alt_ty alt@(DEFAULT, args, rhs) =
+ do { checkL (null args) (mkDefaultArgsMsg args)
+ ; checkAltExpr rhs alt_ty }
+
+lintCoreAlt scrut_ty alt_ty alt@(LitAlt lit, args, rhs) =
+ do { checkL (null args) (mkDefaultArgsMsg args)
+ ; checkTys lit_ty scrut_ty (mkBadPatMsg lit_ty scrut_ty)
+ ; checkAltExpr rhs alt_ty }
where
- check (ty, arg) = checkTys ty (getIdUniType arg) (mkAlgAltMsg4 ty arg)
-
- -- elem: yes, the elem-list here can sometimes be long-ish,
- -- but as it's use-once, probably not worth doing anything different
- -- We give it its own copy, so it isn't overloaded.
- elem _ [] = False
- elem x (y:ys) = x==y || elem x ys
-
-lintPrimAlt scrut_ty alt@(lit,rhs)
- = checkTys (typeOfBasicLit lit) scrut_ty (mkPrimAltMsg alt) `thenL_`
- lintCoreExpr rhs
-
-lintDeflt CoNoDefault scrut_ty = returnL Nothing
-lintDeflt deflt@(CoBindDefault binder rhs) scrut_ty
- = checkTys (getIdUniType binder) scrut_ty (mkDefltMsg deflt) `thenL_`
- addInScopeVars [binder] (
- lintCoreExpr rhs
- )
+ lit_ty = literalType lit
+
+lintCoreAlt scrut_ty alt_ty alt@(DataAlt con, args, rhs)
+ | Just (tycon, tycon_arg_tys) <- splitTyConApp_maybe scrut_ty,
+ tycon == dataConTyCon con
+ = addLoc (CaseAlt alt) $
+ addInScopeVars args $ -- Put the args in scope before lintBinder,
+ -- because the Ids mention the type variables
+ if isVanillaDataCon con then
+ do { addLoc (CasePat alt) $ do
+ { mapM lintBinder args
+ -- FIX! Add check that all args are Ids.
+ -- Check the pattern
+ -- Scrutinee type must be a tycon applicn; checked by caller
+ -- This code is remarkably compact considering what it does!
+ -- NB: args must be in scope here so that the lintCoreArgs line works.
+ -- NB: relies on existential type args coming *after* ordinary type args
+
+ ; con_type <- lintTyApps (dataConRepType con) tycon_arg_tys
+ -- Can just map Var as we know that this is a vanilla datacon
+ ; con_result_ty <- lintCoreArgs con_type (map Var args)
+ ; checkTys con_result_ty scrut_ty (mkBadPatMsg con_result_ty scrut_ty)
+ }
+ -- Check the RHS
+ ; checkAltExpr rhs alt_ty }
+
+ else -- GADT
+ do { let (tvs,ids) = span isTyVar args
+ ; subst <- getTvSubst
+ ; let in_scope = getTvInScope subst
+ subst_env = getTvSubstEnv subst
+ ; case coreRefineTys in_scope con tvs scrut_ty of {
+ Nothing -> return () ; -- Alternative is dead code
+ Just (refine, _) -> updateTvSubstEnv (composeTvSubst in_scope refine subst_env) $
+ do { addLoc (CasePat alt) $ do
+ { tvs' <- mapM lintTy (mkTyVarTys tvs)
+ ; con_type <- lintTyApps (dataConRepType con) tvs'
+ ; mapM lintBinder ids -- Lint Ids in the refined world
+ ; lintCoreArgs con_type (map Var ids)
+ }
+
+ ; let refined_alt_ty = substTy (mkTvSubst in_scope refine) alt_ty
+ -- alt_ty is already an OutType, so don't re-apply
+ -- the current substitution. But we must apply the
+ -- refinement so that the check in checkAltExpr is ok
+ ; checkAltExpr rhs refined_alt_ty
+ } } }
+
+ | otherwise -- Scrut-ty is wrong shape
+ = addErrL (mkBadAltMsg scrut_ty alt)
\end{code}
+%************************************************************************
+%* *
+\subsection[lint-types]{Types}
+%* *
+%************************************************************************
+
+\begin{code}
+lintBinder :: Var -> LintM ()
+lintBinder var | isId var = lintId var >> return ()
+ | otherwise = return ()
+
+lintId :: Var -> LintM OutType
+-- ToDo: lint its rules
+lintId id
+ = do { checkL (not (isUnboxedTupleType (idType id)))
+ (mkUnboxedTupleMsg id)
+ -- No variable can be bound to an unboxed tuple.
+ ; lintTy (idType id) }
+
+lintTy :: InType -> LintM OutType
+-- Check the type, and apply the substitution to it
+-- ToDo: check the kind structure of the type
+lintTy ty
+ = do { ty' <- applySubst ty
+ ; mapM_ checkIdInScope (varSetElems (tyVarsOfType ty'))
+ ; return ty' }
+\end{code}
+
%************************************************************************
%* *
\subsection[lint-monad]{The Lint monad}
%************************************************************************
\begin{code}
-type LintM a = Bool -- True <=> specialisation has been done
- -> [LintLocInfo] -- Locations
- -> UniqSet Id -- Local vars in scope
- -> Bag ErrMsg -- Error messages so far
- -> (a, Bag ErrMsg) -- Result and error messages (if any)
-
-type ErrMsg = PprStyle -> Pretty
+newtype LintM a =
+ LintM { unLintM ::
+ [LintLocInfo] -> -- Locations
+ TvSubst -> -- Current type substitution; we also use this
+ -- to keep track of all the variables in scope,
+ -- both Ids and TyVars
+ Bag Message -> -- Error messages so far
+ (Maybe a, Bag Message) } -- Result and error messages (if any)
+
+instance Monad LintM where
+ return x = LintM (\ loc subst errs -> (Just x, errs))
+ fail err = LintM (\ loc subst errs -> (Nothing, addErr subst errs (text err) loc))
+ m >>= k = LintM (\ loc subst errs ->
+ let (res, errs') = unLintM m loc subst errs in
+ case res of
+ Just r -> unLintM (k r) loc subst errs'
+ Nothing -> (Nothing, errs'))
data LintLocInfo
= RhsOf Id -- The variable bound
- | LambdaBodyOf [Id] -- The lambda-binder
+ | LambdaBodyOf Id -- The lambda-binder
| BodyOfLetRec [Id] -- One of the binders
+ | CaseAlt CoreAlt -- Case alternative
+ | CasePat CoreAlt -- *Pattern* of the case alternative
+ | AnExpr CoreExpr -- Some expression
| ImportedUnfolding SrcLoc -- Some imported unfolding (ToDo: say which)
+\end{code}
-instance Outputable LintLocInfo where
- ppr sty (RhsOf v)
- = ppBesides [ppr sty (getSrcLoc v), ppStr ": [RHS of ", pp_binders sty [v], ppStr "]"]
-
- ppr sty (LambdaBodyOf bs)
- = ppBesides [ppr sty (getSrcLoc (head bs)),
- ppStr ": [in body of lambda with binders ", pp_binders sty bs, ppStr "]"]
+
+\begin{code}
+initL :: LintM a -> Maybe Message {- errors -}
+initL m
+ = case unLintM m [] emptyTvSubst emptyBag of
+ (_, errs) | isEmptyBag errs -> Nothing
+ | otherwise -> Just (vcat (punctuate (text "") (bagToList errs)))
+\end{code}
- ppr sty (BodyOfLetRec bs)
- = ppBesides [ppr sty (getSrcLoc (head bs)),
- ppStr ": [in body of letrec with binders ", pp_binders sty bs, ppStr "]"]
+\begin{code}
+checkL :: Bool -> Message -> LintM ()
+checkL True msg = return ()
+checkL False msg = addErrL msg
- ppr sty (ImportedUnfolding locn)
- = ppBeside (ppr sty locn) (ppStr ": [in an imported unfolding]")
+addErrL :: Message -> LintM a
+addErrL msg = LintM (\ loc subst errs -> (Nothing, addErr subst errs msg loc))
-pp_binders :: PprStyle -> [Id] -> Pretty
-pp_binders sty bs
- = ppInterleave ppComma (map pp_binder bs)
+addErr :: TvSubst -> Bag Message -> Message -> [LintLocInfo] -> Bag Message
+addErr subst errs_so_far msg locs
+ = ASSERT( notNull locs )
+ errs_so_far `snocBag` mk_msg msg
where
- pp_binder b
- = ppCat [ppr sty b, ppStr "::", ppr sty (getIdUniType b)]
-\end{code}
+ (loc, cxt1) = dumpLoc (head locs)
+ cxts = [snd (dumpLoc loc) | loc <- locs]
+ context | opt_PprStyle_Debug = vcat (reverse cxts) $$ cxt1 $$
+ ptext SLIT("Substitution:") <+> ppr subst
+ | otherwise = cxt1
+
+ mk_msg msg = mkLocMessage (mkSrcSpan loc loc) (context $$ msg)
-\begin{code}
-initL :: LintM a -> Bool -> Maybe ErrMsg
-initL m spec_done
- = case (m spec_done [] emptyUniqSet emptyBag) of { (_, errs) ->
- if isEmptyBag errs then
- Nothing
- else
- Just ( \ sty ->
- ppAboves [ msg sty | msg <- bagToList errs ]
- )
- }
-
-returnL :: a -> LintM a
-returnL r spec loc scope errs = (r, errs)
-
-thenL :: LintM a -> (a -> LintM b) -> LintM b
-thenL m k spec loc scope errs
- = case m spec loc scope errs of
- (r, errs') -> k r spec loc scope errs'
-
-thenL_ :: LintM a -> LintM b -> LintM b
-thenL_ m k spec loc scope errs
- = case m spec loc scope errs of
- (_, errs') -> k spec loc scope errs'
-
-thenMaybeL :: LintM (Maybe a) -> (a -> LintM (Maybe b)) -> LintM (Maybe b)
-thenMaybeL m k spec loc scope errs
- = case m spec loc scope errs of
- (Nothing, errs2) -> (Nothing, errs2)
- (Just r, errs2) -> k r spec loc scope errs2
-
-thenMaybeL_ :: LintM (Maybe a) -> LintM (Maybe b) -> LintM (Maybe b)
-thenMaybeL_ m k spec loc scope errs
- = case m spec loc scope errs of
- (Nothing, errs2) -> (Nothing, errs2)
- (Just _, errs2) -> k spec loc scope errs2
-
-mapL :: (a -> LintM b) -> [a] -> LintM [b]
-mapL f [] = returnL []
-mapL f (x:xs)
- = f x `thenL` \ r ->
- mapL f xs `thenL` \ rs ->
- returnL (r:rs)
-
-mapMaybeL :: (a -> LintM (Maybe b)) -> [a] -> LintM (Maybe [b])
- -- Returns Nothing if anything fails
-mapMaybeL f [] = returnL (Just [])
-mapMaybeL f (x:xs)
- = f x `thenMaybeL` \ r ->
- mapMaybeL f xs `thenMaybeL` \ rs ->
- returnL (Just (r:rs))
-\end{code}
+addLoc :: LintLocInfo -> LintM a -> LintM a
+addLoc extra_loc m =
+ LintM (\ loc subst errs -> unLintM m (extra_loc:loc) subst errs)
-\begin{code}
-checkL :: Bool -> ErrMsg -> LintM ()
-checkL True msg spec loc scope errs = ((), errs)
-checkL False msg spec loc scope errs = ((), addErr errs msg loc)
+addInScopeVars :: [Var] -> LintM a -> LintM a
+addInScopeVars vars m =
+ LintM (\ loc subst errs -> unLintM m loc (extendTvInScope subst vars) errs)
-addErrL :: ErrMsg -> LintM ()
-addErrL msg spec loc scope errs = ((), addErr errs msg loc)
+updateTvSubstEnv :: TvSubstEnv -> LintM a -> LintM a
+updateTvSubstEnv substenv m =
+ LintM (\ loc subst errs -> unLintM m loc (setTvSubstEnv subst substenv) errs)
-addErr :: Bag ErrMsg -> ErrMsg -> [LintLocInfo] -> Bag ErrMsg
+getTvSubst :: LintM TvSubst
+getTvSubst = LintM (\ loc subst errs -> (Just subst, errs))
-addErr errs_so_far msg locs
- = ASSERT (not (null locs))
- errs_so_far `snocBag` ( \ sty ->
- ppHang (ppr sty (head locs)) 4 (msg sty)
- )
+applySubst :: Type -> LintM Type
+applySubst ty = do { subst <- getTvSubst; return (substTy subst ty) }
-addLoc :: LintLocInfo -> LintM a -> LintM a
-addLoc extra_loc m spec loc scope errs
- = m spec (extra_loc:loc) scope errs
-
-addInScopeVars :: [Id] -> LintM a -> LintM a
-addInScopeVars ids m spec loc scope errs
- = -- We check if these "new" ids are already
- -- in scope, i.e., we have *shadowing* going on.
- -- For now, it's just a "trace"; we may make
- -- a real error out of it...
- let
- new_set = mkUniqSet ids
-
- shadowed = scope `intersectUniqSets` new_set
- in
--- After adding -fliberate-case, Simon decided he likes shadowed
--- names after all. WDP 94/07
--- (if isEmptyUniqSet shadowed
--- then id
--- else pprTrace "Shadowed vars:" (ppr PprDebug (uniqSetToList shadowed))) (
- m spec loc (scope `unionUniqSets` new_set) errs
--- )
+extendSubstL :: TyVar -> Type -> LintM a -> LintM a
+extendSubstL tv ty m
+ = LintM (\ loc subst errs -> unLintM m loc (extendTvSubst subst tv ty) errs)
\end{code}
\begin{code}
-checkTyApp :: UniType
- -> [UniType]
- -> ErrMsg
- -> LintM (Maybe UniType)
-
-checkTyApp forall_ty ty_args msg spec_done loc scope errs
- = if (not spec_done && n_ty_args /= n_tyvars)
- || (spec_done && n_ty_args > n_tyvars)
- --
- -- Things are *not* OK if:
- --
- -- * Unsaturated type app before specialisation has been done;
- --
- -- * Oversaturated type app after specialisation (eta reduction
- -- may well be happening...);
- --
- -- Note: checkTyApp is usually followed by a call to checkSpecTyApp.
- --
- then (Nothing, addErr errs msg loc)
- else (Just res_ty, errs)
- where
- (tyvars, rho_ty) = splitForalls forall_ty
- n_tyvars = length tyvars
- n_ty_args = length ty_args
- leftover_tyvars = drop n_ty_args tyvars
- inst_env = tyvars `zip` ty_args
- res_ty = mkForallTy leftover_tyvars (instantiateTy inst_env rho_ty)
+checkIdInScope :: Var -> LintM ()
+checkIdInScope id
+ = do { checkL (not (id == oneTupleDataConId))
+ (ptext SLIT("Illegal one-tuple"))
+ ; checkInScope (ptext SLIT("is out of scope")) id }
+
+oneTupleDataConId :: Id -- Should not happen
+oneTupleDataConId = dataConWorkId (tupleCon Boxed 1)
+
+checkBndrIdInScope :: Var -> Var -> LintM ()
+checkBndrIdInScope binder id
+ = checkInScope msg id
+ where
+ msg = ptext SLIT("is out of scope inside info for") <+>
+ ppr binder
+
+checkInScope :: SDoc -> Var -> LintM ()
+checkInScope loc_msg var =
+ do { subst <- getTvSubst
+ ; checkL (not (mustHaveLocalBinding var) || (var `isInScope` subst))
+ (hsep [ppr var, loc_msg]) }
+
+checkTys :: Type -> Type -> Message -> LintM ()
+-- check ty2 is subtype of ty1 (ie, has same structure but usage
+-- annotations need only be consistent, not equal)
+-- Assumes ty1,ty2 are have alrady had the substitution applied
+checkTys ty1 ty2 msg = checkL (ty1 `coreEqType` ty2) msg
\end{code}
-\begin{code}
-checkSpecTyApp :: PlainCoreExpr -> [UniType] -> ErrMsg -> LintM (Maybe ())
-
-checkSpecTyApp expr ty_args msg spec_done loc scope errs
- = if spec_done
- && any isUnboxedDataType ty_args
- && not (an_application_of_error expr)
- then (Nothing, addErr errs msg loc)
- else (Just (), errs)
- where
- -- always safe (but maybe unfriendly) to say "False"
- an_application_of_error (CoVar id) | isBottomingId id = True
- an_application_of_error _ = False
-\end{code}
+%************************************************************************
+%* *
+\subsection{Error messages}
+%* *
+%************************************************************************
\begin{code}
-checkFunApp :: UniType -- The function type
- -> [UniType] -- The arg type(s)
- -> ErrMsg -- Error messgae
- -> LintM (Maybe UniType) -- The result type
+dumpLoc (RhsOf v)
+ = (getSrcLoc v, brackets (ptext SLIT("RHS of") <+> pp_binders [v]))
-checkFunApp fun_ty arg_tys msg spec loc scope errs
- = cfa res_ty expected_arg_tys arg_tys
- where
- (expected_arg_tys, res_ty) = splitTyArgs fun_ty
+dumpLoc (LambdaBodyOf b)
+ = (getSrcLoc b, brackets (ptext SLIT("in body of lambda with binder") <+> pp_binder b))
- cfa res_ty expected [] -- Args have run out; that's fine
- = (Just (glueTyArgs expected res_ty), errs)
+dumpLoc (BodyOfLetRec [])
+ = (noSrcLoc, brackets (ptext SLIT("In body of a letrec with no binders")))
- cfa res_ty [] arg_tys -- Expected arg tys ran out first; maybe res_ty is a
- -- dictionary type which is actually a function?
- = case splitTyArgs (unDictifyTy res_ty) of
- ([], _) -> (Nothing, addErr errs msg loc) -- Too many args
- (new_expected, new_res) -> cfa new_res new_expected arg_tys
+dumpLoc (BodyOfLetRec bs@(_:_))
+ = ( getSrcLoc (head bs), brackets (ptext SLIT("in body of letrec with binders") <+> pp_binders bs))
- cfa res_ty (expected_arg_ty:expected_arg_tys) (arg_ty:arg_tys)
- = case (cmpUniType True{-properly-} expected_arg_ty arg_ty) of
- EQ_ -> cfa res_ty expected_arg_tys arg_tys
- other -> (Nothing, addErr errs msg loc) -- Arg mis-match
-\end{code}
+dumpLoc (AnExpr e)
+ = (noSrcLoc, text "In the expression:" <+> ppr e)
-\begin{code}
-checkInScope :: Id -> LintM ()
-checkInScope id spec loc scope errs
- = if isLocallyDefined id && not (id `elementOfUniqSet` scope) then
- ((), addErr errs (\ sty -> ppCat [ppr sty id, ppStr "is out of scope"]) loc)
- else
- ((), errs)
-
-checkTys :: UniType -> UniType -> ErrMsg -> LintM ()
-checkTys ty1 ty2 msg spec loc scope errs
- = case (cmpUniType True{-properly-} ty1 ty2) of
- EQ_ -> ((), errs)
- other -> ((), addErr errs msg loc)
-\end{code}
+dumpLoc (CaseAlt (con, args, rhs))
+ = (noSrcLoc, text "In a case alternative:" <+> parens (ppr con <+> pp_binders args))
-\begin{code}
-mkCaseAltMsg :: PlainCoreCaseAlternatives -> ErrMsg
-mkCaseAltMsg alts sty
- = ppAbove (ppStr "In some case alternatives, type of alternatives not all same:")
- (ppr sty alts)
-
-mkCaseDataConMsg :: PlainCoreExpr -> ErrMsg
-mkCaseDataConMsg expr sty
- = ppAbove (ppStr "A case scrutinee not a type-constructor type:")
- (pp_expr sty expr)
-
-mkCasePrimMsg :: Bool -> TyCon -> ErrMsg
-mkCasePrimMsg True tycon sty
- = ppAbove (ppStr "A primitive case on a non-primitive type:")
- (ppr sty tycon)
-mkCasePrimMsg False tycon sty
- = ppAbove (ppStr "An algebraic case on a primitive type:")
- (ppr sty tycon)
-
-mkCaseAbstractMsg :: TyCon -> ErrMsg
-mkCaseAbstractMsg tycon sty
- = ppAbove (ppStr "An algebraic case on an abstract type:")
- (ppr sty tycon)
-
-mkDefltMsg :: PlainCoreCaseDefault -> ErrMsg
-mkDefltMsg deflt sty
- = ppAbove (ppStr "Binder in default case of a case expression doesn't match type of scrutinee:")
- (ppr sty deflt)
-
-mkFunAppMsg :: UniType -> [UniType] -> PlainCoreExpr -> ErrMsg
-mkFunAppMsg fun_ty arg_tys expr sty
- = ppAboves [ppStr "In a function application, function type doesn't match arg types:",
- ppHang (ppStr "Function type:") 4 (ppr sty fun_ty),
- ppHang (ppStr "Arg types:") 4 (ppAboves (map (ppr sty) arg_tys)),
- ppHang (ppStr "Expression:") 4 (pp_expr sty expr)]
-
-mkUnappTyMsg :: Id -> UniType -> ErrMsg
-mkUnappTyMsg var ty sty
- = ppAboves [ppStr "Variable has a for-all type, but isn't applied to any types.",
- ppBeside (ppStr "Var: ") (ppr sty var),
- ppBeside (ppStr "Its type: ") (ppr sty ty)]
-
-mkAlgAltMsg1 :: UniType -> ErrMsg
-mkAlgAltMsg1 ty sty
- = ppAbove (ppStr "In some case statement, type of scrutinee is not a data type:")
- (ppr sty ty)
-
-mkAlgAltMsg2 :: UniType -> Id -> ErrMsg
-mkAlgAltMsg2 ty con sty
- = ppAboves [
- ppStr "In some algebraic case alternative, constructor is not a constructor of scrutinee type:",
- ppr sty ty,
- ppr sty con
- ]
+dumpLoc (CasePat (con, args, rhs))
+ = (noSrcLoc, text "In the pattern of a case alternative:" <+> parens (ppr con <+> pp_binders args))
-mkAlgAltMsg3 :: Id -> [Id] -> ErrMsg
-mkAlgAltMsg3 con alts sty
- = ppAboves [
- ppStr "In some algebraic case alternative, number of arguments doesn't match constructor:",
- ppr sty con,
- ppr sty alts
- ]
+dumpLoc (ImportedUnfolding locn)
+ = (locn, brackets (ptext SLIT("in an imported unfolding")))
-mkAlgAltMsg4 :: UniType -> Id -> ErrMsg
-mkAlgAltMsg4 ty arg sty
- = ppAboves [
- ppStr "In some algebraic case alternative, type of argument doesn't match data constructor:",
- ppr sty ty,
- ppr sty arg
- ]
+pp_binders :: [Var] -> SDoc
+pp_binders bs = sep (punctuate comma (map pp_binder bs))
-mkPrimAltMsg :: (BasicLit, PlainCoreExpr) -> ErrMsg
-mkPrimAltMsg alt sty
- = ppAbove (ppStr "In a primitive case alternative, type of literal doesn't match type of scrutinee:")
- (ppr sty alt)
-
-mkRhsMsg :: Id -> UniType -> ErrMsg
-mkRhsMsg binder ty sty
- = ppAboves [ppCat [ppStr "The type of this binder doesn't match the type of its RHS:",
- ppr sty binder],
- ppCat [ppStr "Binder's type:", ppr sty (getIdUniType binder)],
- ppCat [ppStr "Rhs type:", ppr sty ty]
- ]
+pp_binder :: Var -> SDoc
+pp_binder b | isId b = hsep [ppr b, dcolon, ppr (idType b)]
+ | isTyVar b = hsep [ppr b, dcolon, ppr (tyVarKind b)]
+\end{code}
-mkRhsPrimMsg :: Id -> PlainCoreExpr -> ErrMsg
-mkRhsPrimMsg binder rhs sty
- = ppAboves [ppCat [ppStr "The type of this binder is primitive:",
- ppr sty binder],
- ppCat [ppStr "Binder's type:", ppr sty (getIdUniType binder)]
+\begin{code}
+------------------------------------------------------
+-- Messages for case expressions
+
+mkNullAltsMsg :: CoreExpr -> Message
+mkNullAltsMsg e
+ = hang (text "Case expression with no alternatives:")
+ 4 (ppr e)
+
+mkDefaultArgsMsg :: [Var] -> Message
+mkDefaultArgsMsg args
+ = hang (text "DEFAULT case with binders")
+ 4 (ppr args)
+
+mkCaseAltMsg :: CoreExpr -> Type -> Type -> Message
+mkCaseAltMsg e ty1 ty2
+ = hang (text "Type of case alternatives not the same as the annotation on case:")
+ 4 (vcat [ppr ty1, ppr ty2, ppr e])
+
+mkScrutMsg :: Id -> Type -> Message
+mkScrutMsg var scrut_ty
+ = vcat [text "Result binder in case doesn't match scrutinee:" <+> ppr var,
+ text "Result binder type:" <+> ppr (idType var),
+ text "Scrutinee type:" <+> ppr scrut_ty]
+
+
+mkNonDefltMsg e
+ = hang (text "Case expression with DEFAULT not at the beginnning") 4 (ppr e)
+mkNonIncreasingAltsMsg e
+ = hang (text "Case expression with badly-ordered alternatives") 4 (ppr e)
+
+nonExhaustiveAltsMsg :: CoreExpr -> Message
+nonExhaustiveAltsMsg e
+ = hang (text "Case expression with non-exhaustive alternatives") 4 (ppr e)
+
+mkBadPatMsg :: Type -> Type -> Message
+mkBadPatMsg con_result_ty scrut_ty
+ = vcat [
+ text "In a case alternative, pattern result type doesn't match scrutinee type:",
+ text "Pattern result type:" <+> ppr con_result_ty,
+ text "Scrutinee type:" <+> ppr scrut_ty
+ ]
+
+mkBadAltMsg :: Type -> CoreAlt -> Message
+mkBadAltMsg scrut_ty alt
+ = vcat [ text "Data alternative when scrutinee is not a tycon application",
+ text "Scrutinee type:" <+> ppr scrut_ty,
+ text "Alternative:" <+> pprCoreAlt alt ]
+
+------------------------------------------------------
+-- Other error messages
+
+mkAppMsg :: Type -> Type -> CoreExpr -> Message
+mkAppMsg fun_ty arg_ty arg
+ = vcat [ptext SLIT("Argument value doesn't match argument type:"),
+ hang (ptext SLIT("Fun type:")) 4 (ppr fun_ty),
+ hang (ptext SLIT("Arg type:")) 4 (ppr arg_ty),
+ hang (ptext SLIT("Arg:")) 4 (ppr arg)]
+
+mkKindErrMsg :: TyVar -> Type -> Message
+mkKindErrMsg tyvar arg_ty
+ = vcat [ptext SLIT("Kinds don't match in type application:"),
+ hang (ptext SLIT("Type variable:"))
+ 4 (ppr tyvar <+> dcolon <+> ppr (tyVarKind tyvar)),
+ hang (ptext SLIT("Arg type:"))
+ 4 (ppr arg_ty <+> dcolon <+> ppr (typeKind arg_ty))]
+
+mkTyAppMsg :: Type -> Type -> Message
+mkTyAppMsg ty arg_ty
+ = vcat [text "Illegal type application:",
+ hang (ptext SLIT("Exp type:"))
+ 4 (ppr ty <+> dcolon <+> ppr (typeKind ty)),
+ hang (ptext SLIT("Arg type:"))
+ 4 (ppr arg_ty <+> dcolon <+> ppr (typeKind arg_ty))]
+
+mkRhsMsg :: Id -> Type -> Message
+mkRhsMsg binder ty
+ = vcat
+ [hsep [ptext SLIT("The type of this binder doesn't match the type of its RHS:"),
+ ppr binder],
+ hsep [ptext SLIT("Binder's type:"), ppr (idType binder)],
+ hsep [ptext SLIT("Rhs type:"), ppr ty]]
+
+mkRhsPrimMsg :: Id -> CoreExpr -> Message
+mkRhsPrimMsg binder rhs
+ = vcat [hsep [ptext SLIT("The type of this binder is primitive:"),
+ ppr binder],
+ hsep [ptext SLIT("Binder's type:"), ppr (idType binder)]
]
-mkTyAppMsg :: PlainCoreExpr -> ErrMsg
-mkTyAppMsg expr sty
- = ppAboves [ppStr "In a type application, either the function's type doesn't match",
- ppStr "the argument types, or an argument type is primitive:",
- pp_expr sty expr]
+mkUnboxedTupleMsg :: Id -> Message
+mkUnboxedTupleMsg binder
+ = vcat [hsep [ptext SLIT("A variable has unboxed tuple type:"), ppr binder],
+ hsep [ptext SLIT("Binder's type:"), ppr (idType binder)]]
-mkSpecTyAppMsg :: PlainCoreExpr -> ErrMsg
-mkSpecTyAppMsg expr sty
- = ppAbove (ppStr "Unboxed types in a type application (after specialisation):")
- (pp_expr sty expr)
+mkCoerceErr from_ty expr_ty
+ = vcat [ptext SLIT("From-type of Coerce differs from type of enclosed expression"),
+ ptext SLIT("From-type:") <+> ppr from_ty,
+ ptext SLIT("Type of enclosed expr:") <+> ppr expr_ty
+ ]
-pp_expr sty expr
- = pprCoreExpr sty pprBigCoreBinder pprTypedCoreBinder pprTypedCoreBinder expr
+mkStrangeTyMsg e
+ = ptext SLIT("Type where expression expected:") <+> ppr e
\end{code}
projects / ghc-hetmet.git / blobdiff